Brake calipers in general are not specific to a model or manufacturer, but are specific to an application. e.g. stub-axles, hubs and rotors are designed around existing calipers. This goes for most brakes on most cars.
When I got these:
They were amongst 50+ pairs including Bigreds. I wanted nothing but the '86 like those in Supermans pic.
Mr Porschapart had this type of caliper that had the script in cast letters, with printed (small in white, same as big reds) script and he had a pair in red powdercoat that were blank. One pair was black with a Brembo script. All had the cast Brembo logo on the inside.
All 'original' 951 calipers have the script in cast letters, Mr Porschapart suggested that the others were replacement parts sourced from Brembo and not Porsche as the labelled units are only available from Porsche main dealers. He said the axial mount 4pots and the bigreds retail at.. wait for it... One thoasand and two thoasand pounds respectivley, EACH
I paid £60 each and was happy
Second hand cars have second hand brakes I told myself.
Matt