NOS Lucas rear side marker lens 54580315 in the original bag dated 7-70.
Markings on the lens: Lucas, REGD.DES., 938648, SAE P1 69, L841.
These lenses will fit Type L841 lamps.
Listed to fit Triumph Spitfire 71-80, Triumph GT6 71-73, and MG Midget 70-80, possibly others. There is a Mopar Chrysler part # as well, 75061518 which would make me think 71-77 Dodge Colt or Plymouth Cricket, check your application.