{
  "factory_source": "https://www.spridgets.de/downloads/Parts-1977.pdf#page=141",
  "factory_access": "PDF p141 / printed107-E26 visually read; topology and counts, no dimensioned seat or procedure.",
  "factory_counts": {
    "seats_21A137": 2,
    "bolts_53K1368": 8,
    "shakeproof_washers_LWN405": 8,
    "nuts_LNZ205_or_LNZ105": 8
  },
  "supplier_source": "https://www.mgocspares.co.uk/parts/mg/midget/suspension-steering/front-suspension/front-suspension",
  "supplier_photo": "https://www.mgocspares.co.uk/ImageHandler/233197w700h700/21a137z?Sequence=233197&Width=700&Height=700",
  "supplier_photo_observation": "Four mounting ears and raised closed center. Shape comparison only; no scaled tracing or identity claim.",
  "supplier_fastener_comparison": "53K1368 listed 5/16 UNF x 3/4 inch; 7.9375 mm smooth nominal shank and 19.05 mm underhead length. Factory washer roles used; current supplier plain-washer alternative not silently substituted.",
  "owner_measurements_applied": false,
  "nodes": {
    "left": {
      "factory_source": "https://www.spridgets.de/downloads/Parts-1977.pdf#page=141",
      "supplier_source": "https://www.mgocspares.co.uk/parts/mg/midget/suspension-steering/front-suspension/front-suspension",
      "limits": "Factory topology: two 21A137 seats, eight 53K1368 bolts, eight LWN405 shakeproof washers and alternate LNZ205/LNZ105 nuts. Supplier 21A137Z photo shows four ears and raised closed center; it is a replacement comparison, not fitted identity. Supplier screw nominal 5/16 UNF x 3/4 in gives 7.9375 mm diameter and 19.05 mm underhead length only. Seat profile, 3 mm sections, 95 mm mounting radius, hole clocking, bores, head/nut/washer sections and bolt orientation are estimates. Smooth washers represent unloaded shakeproof roles without teeth. No actual thread, engagement, spring loading, fitted clearance, safe release or verified removal path. Existing coil geometry/position is retained; its lower wire remains about 7.6 mm above the estimated seat face, not a verified working contact. Positive X is vehicle left after the viewer reflects legacy drawing roots. Existing coil IDs and physical positions are retained.",
      "center_mm": [
        381.00000000000006,
        234.5266666666667,
        1016.0
      ],
      "estimated_mount_centers_mm": [
        [
          448.1751442127221,
          234.5266666666667,
          1083.175144212722
        ],
        [
          313.82485578727807,
          234.5266666666667,
          1083.175144212722
        ],
        [
          313.824855787278,
          234.5266666666667,
          948.824855787278
        ],
        [
          448.17514421272205,
          234.5266666666667,
          948.824855787278
        ]
      ],
      "estimated_bore_radius_mm": 4.3,
      "estimated_seat_gauge_mm": 3,
      "estimated_pan_sheet_top_mm": 237.06666666666672,
      "supplier_nominal_bolt_diameter_mm": 7.9375,
      "supplier_nominal_bolt_underhead_length_mm": 19.05,
      "owner_dimensions_applied": false,
      "estimated_lower_coil_wire_to_flat_seat_gap_mm": 7.61999999999996
    },
    "right": {
      "factory_source": "https://www.spridgets.de/downloads/Parts-1977.pdf#page=141",
      "supplier_source": "https://www.mgocspares.co.uk/parts/mg/midget/suspension-steering/front-suspension/front-suspension",
      "limits": "Factory topology: two 21A137 seats, eight 53K1368 bolts, eight LWN405 shakeproof washers and alternate LNZ205/LNZ105 nuts. Supplier 21A137Z photo shows four ears and raised closed center; it is a replacement comparison, not fitted identity. Supplier screw nominal 5/16 UNF x 3/4 in gives 7.9375 mm diameter and 19.05 mm underhead length only. Seat profile, 3 mm sections, 95 mm mounting radius, hole clocking, bores, head/nut/washer sections and bolt orientation are estimates. Smooth washers represent unloaded shakeproof roles without teeth. No actual thread, engagement, spring loading, fitted clearance, safe release or verified removal path. Existing coil geometry/position is retained; its lower wire remains about 7.6 mm above the estimated seat face, not a verified working contact. Positive X is vehicle left after the viewer reflects legacy drawing roots. Existing coil IDs and physical positions are retained.",
      "center_mm": [
        -381.00000000000006,
        234.5266666666667,
        1016.0
      ],
      "estimated_mount_centers_mm": [
        [
          -313.824855787278,
          234.5266666666667,
          1083.175144212722
        ],
        [
          -448.17514421272205,
          234.5266666666667,
          1083.175144212722
        ],
        [
          -448.1751442127221,
          234.5266666666667,
          948.824855787278
        ],
        [
          -313.82485578727807,
          234.5266666666667,
          948.824855787278
        ]
      ],
      "estimated_bore_radius_mm": 4.3,
      "estimated_seat_gauge_mm": 3,
      "estimated_pan_sheet_top_mm": 237.06666666666672,
      "supplier_nominal_bolt_diameter_mm": 7.9375,
      "supplier_nominal_bolt_underhead_length_mm": 19.05,
      "owner_dimensions_applied": false,
      "estimated_lower_coil_wire_to_flat_seat_gap_mm": 7.61999999999996
    }
  },
  "workshop": "Exploded parts drawing is not a spring release procedure. Translations are illustrative only. No safe support state, torque, spring restraint, loaded fit or verified removal path established.",
  "limits": "Factory topology: two 21A137 seats, eight 53K1368 bolts, eight LWN405 shakeproof washers and alternate LNZ205/LNZ105 nuts. Supplier 21A137Z photo shows four ears and raised closed center; it is a replacement comparison, not fitted identity. Supplier screw nominal 5/16 UNF x 3/4 in gives 7.9375 mm diameter and 19.05 mm underhead length only. Seat profile, 3 mm sections, 95 mm mounting radius, hole clocking, bores, head/nut/washer sections and bolt orientation are estimates. Smooth washers represent unloaded shakeproof roles without teeth. No actual thread, engagement, spring loading, fitted clearance, safe release or verified removal path. Existing coil geometry/position is retained; its lower wire remains about 7.6 mm above the estimated seat face, not a verified working contact. Positive X is vehicle left after the viewer reflects legacy drawing roots. Existing coil IDs and physical positions are retained."
}