Legacy Metrics

1957 Buick Roadmaster Convertible Series 70

7D4021740roadUnited States
Engine
364 cu. in. OHV V8, 300 bhp
Colour
Carlsbad Black with red

The 1957 Buick Roadmaster convertible is among the rarest and most desirable configurations of that model year, with only 4,364 examples produced. Riding on a 127.5-inch wheelbase and powered by a 364 cu. in. 'nailhead' V-8 producing 300 bhp, it features the longer, lower body introduced for 1957 with distinctive sweepspear trim and radiused rear fenders. This example received a comprehensive frame-off restoration under prior ownership and was subsequently displayed in the Kughn Collection at prominent concours events.

Ownership

  1. Auction sale
  2. Date unknown
    Prior owner who commissioned restoration
    partial documentation

    This owner undertook a thorough frame-off restoration to a high standard, resulting in the excellent condition visible today.

  3. Date unknownAcquisition unknown
    Kughn Collection
    partial documentation

    The car was exhibited at multiple concours events during this owner's tenure, reflecting pride in its quality and presentation.

Competition

  1. 2011
    2011 Concours d'Elegance of America at St. John's

    Car was displayed as an exhibit while in the Kughn Collection.

  2. 2011
    2011 Bay Harbor Vintage Car & Boat Festival

    Shown at this Northern Michigan event in the same year as the St. John's concours appearance.

Maintenance & restoration

  1. Restoration

    A thorough frame-off, nut-and-bolt restoration was carried out, resulting in well-fitted body panels, a deep Carlsbad Black and red paint finish, a properly detailed engine bay with correct finishes and a Delco battery, a restored and carpeted trunk, and a pristine red leather interior.

    Work was completed under prior ownership; recorded mileage of 22,327 is believed to include pre-restoration miles.

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Each chassis record is compiled from public auction archives and links to its source material. Ownership, competition and maintenance entries are extracted from those catalogue listings by an LLM, which can make mistakes — please contact us with any corrections. The summary is Legacy Metrics’ own writing; we do not reproduce catalogue text.

“Full” and “partial” documentation labels indicate how well each entry is corroborated in the underlying sources, not an audit of the car’s physical paperwork. Names of recent or living owners are withheld for privacy.

Legacy Metrics — 1957 Buick Roadmaster Convertible Series 70