1970 HELLA LAMP

POSSIBLY
COMMERCIAL TRUCK / BUS
TAIL LIGHT ASSEMBLY

I was unable to identify exactly which vehicle this is from.
Any help is appreciated?
Part numbers on the lens face are;
SRBBL 154-2 ZR
SAE-STIAR 70
THK27
It also has an "R" at the top. Perhaps right side?
Lens face has minor scuffing. There is a small crack in the back up portion (I can not feel it while rubbing a finger nail over it). Tabs and prongs are good and intact on the rear of lens as well as studs.

Thanks for viewing
4080-143-040