Euro Panteras were mandated to use amber back-up lights in the taillight lenses by international law. Maserati and a few other Euro cars used identical lenses. Similarly, U.S Panteras were required to have clear (or opaque white) back-up lenses. No rhyme nor reason for either rule.
Carello and Altissima made lenses for DeTomaso and Ford, with minor variations (Altissima used two-piece lenses). And then there were the so-called GR-4 lights used on the racers & adapted from a big Alfa sedan that was never sold in the U.S. Outside of personal aesthetics, more important is how reflective the interior housings are after 45 years. This affects the brightness of the tail, stop and back-up lights and maybe catch the attention of normally half-asleep drivers behind you.