Ok.. to add some history.. Bristol like Aston Martin and other bespoke high-end cars would often purchase switchgear, elec components and window handles accessories etc from the various British suppliers rather than invest in bespoke components.
The tail lights and housing on the 400 series Bristol's used lucas lamps made for Rootes ... Note that Rootes to save money switched away from the bespoke alpine series I-3 rear lamps to the same units they used on all their minx, husky, sceptre, superminx, vogue, gazelle, alpine, rapier .. the same lamps are used on Turner sports cars as well. Small mfg would just purchase the parts
The 70s v8 astons used the hillman hunter tail light units...
This 'parts bin" raiding is still comon today....