{
  "schema": "front-disc-retention-cover-validation-v1",
  "baseline_commit": "a039adee",
  "scope": "Native front hub/disc and formed cover comparison; no fitted/loaded/travel or removal-path proof.",
  "source_parts": 30,
  "positive_valid_step_solids": 52,
  "unchanged_source_mesh_groups": [
    "front_left_inner_bearing_boundary_comparison",
    "front_left_outer_bearing_boundary_comparison",
    "front_left_hollow_bearing_distance_piece_comparison",
    "front_left_inner_hub_seal_unloaded_boundary_envelope",
    "front_left_separate_spindle_washer_comparison",
    "front_left_unthreaded_castellated_retaining_nut_envelope",
    "front_left_separate_hollow_grease_cap_envelope",
    "front_left_unbent_split_pin_stem_and_loop_comparison",
    "front_left_four_wheel_stud_shank_and_head_envelopes",
    "front_left_four_separate_unthreaded_wheel_nut_envelopes",
    "front_right_inner_bearing_boundary_comparison",
    "front_right_outer_bearing_boundary_comparison",
    "front_right_hollow_bearing_distance_piece_comparison",
    "front_right_inner_hub_seal_unloaded_boundary_envelope",
    "front_right_separate_spindle_washer_comparison",
    "front_right_unthreaded_castellated_retaining_nut_envelope",
    "front_right_separate_hollow_grease_cap_envelope",
    "front_right_unbent_split_pin_stem_and_loop_comparison",
    "front_right_four_wheel_stud_shank_and_head_envelopes",
    "front_right_four_separate_unthreaded_wheel_nut_envelopes"
  ],
  "revised_source_mesh_groups": [
    "front_left_connected_stepped_hub_and_two_pattern_wheel_flange",
    "front_left_connected_solid_rotor_hat_and_four_bored_mounts",
    "front_left_four_separate_disc_to_hub_screw_envelopes",
    "front_right_connected_stepped_hub_and_two_pattern_wheel_flange",
    "front_right_connected_solid_rotor_hat_and_four_bored_mounts",
    "front_right_four_separate_disc_to_hub_screw_envelopes"
  ],
  "added_source_mesh_groups": [
    "front_left_formed_disc_dust_cover_with_three_mounting_roles_comparison",
    "front_left_single_dust_cover_screw_and_unloaded_washer_comparison",
    "front_right_formed_disc_dust_cover_with_three_mounting_roles_comparison",
    "front_right_single_dust_cover_screw_and_unloaded_washer_comparison"
  ],
  "disc_retention_revision": {
    "factory_source": "https://www.spridgets.de/downloads/Parts-1977.pdf#page=142",
    "factory_role": "BTA370,8 per car; distinct from wheel studs and nuts",
    "catalog_size_sources": [
      "https://rimmerbros.com/Item--i-BTA370",
      "https://www.minispares.com/bta370-drive-flange-bolt-12-wheel"
    ],
    "catalog_thread": "3/8 UNF",
    "catalog_major_diameter_mm": 9.525,
    "catalog_underhead_length_mm": 17.4625,
    "former_estimated_major_diameter_mm": 6,
    "former_estimated_underhead_length_mm": 16,
    "retained_inboard_underhead_face_local_x_mm": 8,
    "source_tip_local_x_mm": 25.4625,
    "retained_wheel_mount_face_local_x_mm": 20,
    "source_tip_beyond_mount_face_mm": 5.462499999999999,
    "estimated_clearance_bore_radius_mm": 4.95,
    "estimated_outer_flange_lug_radius_mm": 12,
    "estimated_head_circumdiameter_mm": 16.5,
    "estimated_head_height_mm": 4.5,
    "limits": "Factory supplies role/count; modern suppliers supply nominal bolt size, not an owner fastener measurement or fitted identity. Inboard head-face pose stays as a construction convention; actual direction, grade, thread receiver/engagement and wheel clearance remain unresolved. No bolt shortening, body/axle move or fitted machining size is inferred. Smooth envelopes omit threads. The historical mesh name retains screw_envelopes for existing links."
  },
  "source_neighbor_contacts_mm3": {
    "left_formed_disc_dust_cover_with_three_mounting_roles_comparison__front_left_bored_swivel_carrier_spindle_and_web_reference": 138.2538,
    "right_formed_disc_dust_cover_with_three_mounting_roles_comparison__front_right_bored_swivel_carrier_spindle_and_web_reference": 138.2538
  },
  "sampled_cover_and_wheel_contacts_mm3": {
    "left_cover__wheel": 0.0,
    "left_disc_bolts__wheel": 838.50654,
    "left_cover__connected_solid_rotor_hat_and_four_bored_mounts": 0.0,
    "left_cover__connected_stepped_hub_and_two_pattern_wheel_flange": 0.0,
    "right_cover__wheel": 0.0,
    "right_disc_bolts__wheel": 838.507556,
    "right_cover__connected_solid_rotor_hat_and_four_bored_mounts": 0.0,
    "right_cover__connected_stepped_hub_and_two_pattern_wheel_flange": 0.0
  },
  "held_source_sha256": {
    "cars/1975-mg-midget/cad/wheel-profile-reference.json": "46512939f693c68c8f38c073fa2bce2367816bdf015dcbc9f7461de6085318ee",
    "cars/1975-mg-midget/cad/wheel-profile-reference.step": "8842a7c18f0dd4cb906d050e5c660f33cb90b1f99e6dd9152e5188d57b6309c4",
    "cars/1975-mg-midget/cad/front-kingpin-reference.json": "dc54f690b5a01c4fbe0b1a24a3764735daec6a0dcf418723b3ccd49cda0aa308",
    "cars/1975-mg-midget/cad/front-kingpin-reference.step": "e84bbe8c6c6e1b4ef601881c48894bbb189777953701c2d03ca834a28669dd29",
    "cars/1975-mg-midget/cad/front-caliper-reference.json": "455b4ea09f126a8221cc84d696b0a3ec8aae1a1e68e9b63d0c1dca528f0543b5",
    "cars/1975-mg-midget/cad/front-caliper-reference.step": "302631a316175edded50d9271ae4824f2fa5a825656d713d9b95e35b84ff667f",
    "cars/1975-mg-midget/cad/front-fulcrum-reference.json": "151bb2f528be8efbfe1e192fa2942e5b9584444494f3b54e75bb87a7e94308f6",
    "cars/1975-mg-midget/cad/front-fulcrum-reference.step": "13e461d9c8dd51b7d3eea773a89548e236669a763917157977c72834d87a4a4a",
    "cars/1975-mg-midget/cad/transmission-reference.json": "b7c465080d634928a1d47fa31b94fb1a77ffb4cd85231b2c2001e2b483b91af7",
    "cars/1975-mg-midget/cad/transmission-reference.step": "c90cfd19b5e4fc02480e25b4d9904d71465805008505e3ad3598dcfd5c9710e5"
  },
  "limits": "Cover/carrier source overlaps and nominal disc-bolt/wheel overlap remain unregistered construction gaps. Catalog nominal size does not establish actual fitted identity, bolt direction, stack, clearance, loaded support, safe access or a verified replacement path. Formed cover presence is unverified. Historical rostyle-forming-validation.json used the baseline hub, not this revision.",
  "source_sha256": {
    "front-hub-reference.json": "a0c5ad9a1eff687e3e7a15147a1ece5fe7f28cf7330e17fc5adbba88df1a304f",
    "front-hub-reference.step": "62d94e86358693782eee980b1bb8873ba1a2e801db336284af33f1a967eeea6a"
  },
  "browser_validation": {
    "nativeFrontHubMeshes": 30,
    "finiteVertices": 44812,
    "heldSurroundingMeshSamples": 1540,
    "allNativeSourceStatusesReady": 74,
    "sourceMappingPickingAndMetricPlacement": true,
    "coarseHubAndShieldMeshesReplaced": true,
    "productionCoverSelection": true,
    "productionReloadWithoutHooks": true,
    "pageErrors": [],
    "study_images_loaded": true,
    "native_downloads": true,
    "mobile_study_overflow": false
  }
}