Join the floor
to its tunnel.
Thin floors now meet the declared tunnel base and separate inner-sill webs. A hollow tunnel, an estimated rear flare, open rear-floor half-channels and a lower heelboard replace coarse surfaces and solid bars around the cabin and driveline.
Reconcile the references first
The former floor’s inner contour left wedges beside the tunnel, while its outboard edge ran through the solid sill envelope. Floor edges now follow the tunnel section stations and meet the inner-sill web at X magnitude .66. The floor top remains Y=.35; all eight existing seat-fixing stations and holes are retained. These are model construction corrections, not changes derived from owner measurements.
The old narrow rear tunnel also crossed the estimated banjo housing. A declared rear flare surrounds that existing comparison, the rear-floor channel gains a central mouth, and two open-rear tube reliefs remove the static sidewall clash. The heelboard opening follows the same tunnel profile. The gearbox support, rear axle, seats and their placements remain unchanged. These constructed openings cannot establish actual clearance or suspension travel.
Architecture and source classes
The manufacturer’s body drawing distinguishes floor panels, inner sills, centre crossmember and heelboard skins/reinforcements. These roles inform the model, without identifying a fitted pressing or weld map. The rear-floor crossmember here is not assigned the manufacturer’s centre-crossmember part number; its connection to the actual body remains unverified.
Owner IMG_6341 supplies cabin/sill context and IMG_6919 supplies underside context, without a calibrated hidden floor/tunnel survey. No direct owner measurements are applied. Seat and driveline references retain their earlier source classes and uncertainty.
| Construction | Basis / limit |
|---|---|
| Floor | Estimated 1.5 mm section below retained top Y=.35. Outer X magnitude changes from .70 to .66; inner edge follows current tunnel widths. Seat bores stay at their existing stations. |
| Inner sills | Estimated webs at X magnitude .66, top/bottom returns to .71, Y=.25–.50 and Z=-1.255–.395. Open ends and outward faces do not reconstruct complete sill boxes, jacking apertures or reinforcements. |
| Tunnel | Prior front/mid stations retained. Rear half-width grows to an estimated .22 instead of .12, around the existing 165 mm banjo comparison. Crown heights remain drawing choices. Radial shell construction is not a uniform normal sheet offset. |
| Rear tube reliefs | Estimated 33 mm radius around the existing 32 mm-radius axle-tube comparison at Y=.39/Z=-1.20. The 1 mm radial display allowance is not fitted clearance, a factory cutout or a suspension envelope. |
| Lever mouth | Estimated ellipse X/Z radii .08/.10 at Z=-.32 in the existing gaiter region. No seal fit, shift travel or service opening is established. |
| Rear-floor channels | Prior X span/Z station and lower Y retained, with the top moved 18.43 mm down to the new floor underside. A declared .44-unit central mouth replaces the solid middle. These are construction corrections, not measured packing or clearance. |
| Lower heelboard | Estimated section below the existing upper rear bulkhead/boot-floor level, with a matching tunnel mouth. Actual skins, lap order and spring-hanger reinforcement remain unresolved. |
Floor pressings, plugs/drains, captive nuts, seat/restraint reinforcements, actual sill closure, jacking-point variants, weld pitch, corrosion and repaired seams are not reconstructed. No strength, restraint rating, loaded axle clearance, body alignment or repair template follows from these sections.
Workshop use
Keep these body references fixed while inspecting seat fixings, gearbox/propeller shaft and the rear axle. The open underside and lever mouth explain surrounding structure; they do not verify gearbox extraction, driveline travel or tool access. Independent selection and hiding do not make welded panels detachable, and no cutting/welding, lifting or removal procedure is supplied.
Native export
Validation covers 16 valid solids, retained seat bores with neighboring material, open tunnel bottom/lever mouth/tube reliefs, shared floor/tunnel stations, open sections, metric placement and fixed body inspection ownership. Per-part CAD intersections against the existing rear-axle STEP at its declared body transform are zero for these seven source parts. This is static comparison geometry, not a minimum or fitted clearance/travel result.
The gearbox body-gaiter study now follows this curved tunnel with a separate hollow cuff, flange and retainer. Four shared construction holes follow estimated local surface normals; they are not factory body coordinates or a drilling/repair template. Six non-tunnel source meshes remain unchanged.
Bounded sill sections at the rear arch
The former inner sill ran back beyond the rear axle station and below the visible outer sill. Its rear end passed through the rear tyre reference. The revised inner sill stops at the existing rear-arch front, Z=−.82 body units, and reaches the existing footwell front at Z=+.35. Its lower return now shares the outer sill’s retained Y=.30 datum. These are coordinated construction boundaries, not owner measurements.
Paired native outer skins now replace the browser-only skins and top ribbons. Their cambered outside surfaces follow the retained visible body profile; top and lower returns meet the inner return edges at X magnitude .71. Outer fronts retain Z=.23, leaving the forward lower-wing/footwell closure to reconcile. The estimated 1.5 mm projected sections, open ends, joints and mirroring are reference construction. They do not reconstruct fitted hems, laps, welds, strength or corrosion.
IMG_6329 and IMG_6341 establish the visible black rocker, door aperture and rear wheel-opening relationship. British Motor Heritage distinguishes CZJ176/177 inner sills, floors and footwell panels. Its skin-panel table distinguishes 1975-on twin-jacking-point CZJ694/695 outer sills from earlier applications. None identifies this car’s installed repair panels or supplies the modeled sections. No jack apertures or reinforcement locations are inferred.
What the checks establish: the nine source groups contain 18 valid positive STEP solids; five former mesh payloads remain identical. The old inner-sill/tyre source overlap was about 3,221 mm³ per side; the revised inner and outer sills have zero static overlap with the unchanged tyre sources. Return-edge material witnesses and all eight retained seat-floor axes pass. This does not verify fitted wheel clearance or suspension travel.
The unchanged floor still overlaps each rear tyre reference by about 2,326 mm³. Rear floor, wheelhouse and seat/body registration need reconciliation together; the sill revision does not resolve that interface. No seat holes or floor corners were moved to erase it. These are model discrepancies, not evidence of interference on the actual car.
All sill/body groups remain fixed during illustrative separation. Isolation exposes sections; it does not make welded panels detachable. No cutting order, bracing, support or jacking point, repair suitability, weld schedule or verified replacement/removal path is established.
Seats, floor and wheelhouses together
The former seats sat mostly behind the modeled door openings. IMG_6341 shows the cushions occupying the doorway, with rear edges near the B-post. Both complete seat assemblies now move forward by an estimated 317.5 mm: upholstery, headrests, frames, runners, catches and fixing references retain their shapes and relative positions. The eight floor-hole references follow the same translation.
The selected shift aligns the retained native cushion’s rear extent with the existing estimated B-post boundary. It is a coherent construction choice, not a calibrated measurement from the photograph, a factory seat station, an actual rail setting or an ergonomic fit. Seat dimensions, X/Y stations, recline and body aperture stay. The opposite seat repeats the choice without proof that both fitted seats share an adjustment.
The surrounding rear floor
Rear floor corners now step inward to the retained inner-wheelhouse plane, X magnitude .47. The wheelhouse lower webs extend from their former axle-height chords down to the retained floor at Y=.35. Wheelhouse radius, wheel/axle poses, roof and reliefs stay; no wheelhouse material is removed. Native inner/outer sills, tunnel, spring hangers, body restraints, folded hood and the engine/body frame remain at their previous references.
British Motor Heritage’s rear-body drawing distinguishes inner wheelhouses, wheelarch reinforcements and the rubber-bumper CZJ568 boot floor with cockpit rear floor. Its front/centre drawing separates floor and sill panels. Factory seat plates separate cushion, frame and runner roles. These sources establish assembly roles, not the new seat station, floor outline, wall skirt, fitted welds or body dimensions.
Checks and unresolved interfaces
All 20 native upholstery/support groups retain volume and bounds under the same rigid translation. Four STEP exports contain 162 valid positive solids. Seven cabin and 16 rear-body mesh payloads remain identical. All eight new floor bores are open with neighboring floor material; witnesses confirm material on both sides of the shared floor/wall boundary.
The floor/tyre source overlaps of about 2,326 mm³ per side and the seat-frame/wheelhouse overlaps of about 1,404 mm³ per side are now zero in the sampled static sources. The independent heelboard still overlaps each wheelhouse by about 59.5 mm³; its join/lap and wider rear-body registration remain unresolved. These results do not prove actual-car clearances, loaded support or a collision-free seat adjustment.
Workshop limit: no actual holes are specified for drilling, and the new floor outline is not a cutting template. Body/belt anchors remain untouched as unverified comparisons; belt compatibility, seat-slide/recline travel, door clearance, fixing strength, safe support and a verified seat or floor replacement sequence are not established. General separation and the door pose remain illustrations.