MG MGA

The British Motor Industry Heritage Trust (BMIHT) at the British Motor Museum, Gaydon, will supply a Heritage Certificate for any MGA on chassis-number request. This is the single decisive documentation item: it confirms build date, factory colour, factory equipment and dispatch destination. The RM Sotheby's Hershey 2018 Lot 223 catalogue for chassis GHNL2/106350 (verified from the lot page, 6 July 2026) is explicit on this point — the car is described verbatim as 'Accompanied by British Motor Industry Heritage Trust (BMIHT) Certificate and service invoices' — and this is a value-positive factor at every tier. Also verify against the BMIHT record whether a car being sold as a 'Twin Cam' or 'Mk II Deluxe' is a genuine factory example versus a later fitment / conversion.

The Twin Cam (2,111 units, own chassis prefix YD/YM) and the Mk II Deluxe (~313 units for 1962 per published breakdowns: 290 roadsters + 23 coupés) share the four-wheel Dunlop centre-lock disc wheels and four-wheel disc brakes, but the Twin Cam has the DOHC engine while the Deluxe has the pushrod Mk II engine. The RM Sotheby's Gene Ponder 2022 Lot 3176 catalogue quotes '395' for the Deluxe, but that 395 figure is the combined 1600 Deluxe (82) + Mk II Deluxe (~313) total and is likely conflated when applied to a Mk II Deluxe car. Genuine Twin Cams command a marked premium over Deluxes; genuine Deluxes command a premium over standard Mk IIs. Verify against BMIHT which car you are actually buying, and inspect the engine numbering against the BMIHT record — a Twin Cam whose original DOHC engine has been swapped for a pushrod unit is materially less valuable than one with its matching-numbers twin-cam.

The DOHC 1,588cc twin-cam engine is the Twin Cam's defining feature and the model's historically known weak spot: piston / bore burning and detonation issues on period fuel plagued the model in service and were the main reason the Twin Cam was discontinued after only 2,111 units. Modern rebuilds by a recognised specialist (with modern pistons, correct compression and correct ignition mapping) resolve the issue but require documented specialist attention. On any Twin Cam PPI: compression test on all four cylinders, leak-down test, ignition timing verification, and receipts for the last engine rebuild from a recognised Twin Cam specialist.

The MGA has a separate steel body over a ladder chassis and rusts predictably: chassis rails (especially the outriggers behind the front wheels and forward of the rear wheels), sills, floor pans, A-post base, door bottoms, front wing lower panels, rear wing lower panels and boot floor. Any body-off restoration should have addressed all of these; photo documentation of a body-off is a value factor on any car above the driver-quality tier. Cars that have never been off the chassis and are being sold as 'original paint' should be very carefully inspected underneath — the chassis is the structural item.

Period Lucas electrics are the historical joke about the model — modern re-wiring loom kits from established suppliers are common and preferable to a tired original loom. Roadsters have removable side curtains rather than wind-up windows, and the hood is detachable — inspect the frame for straightness, the fabric for shrinkage, and the header rail seal. Interior refurbishment (leather seats, carpets, trim) is well-supported by the specialist trade in both the UK and USA. Coupes have proper wind-up windows and a fixed roof, but suffer their own headliner and window-frame corrosion issues.