original aftermarket A/C, Frigette Strato V

That's interesting. Did you make up the compressor brackets on the spot?
You can see these were welded up.

Brought that car to NJ from Michagan in '89 IIRC.
Arizona car. Sold by Town & Country Chrysler in Pheonix.
Had 52,000 miles on it when I bought it. Well more like 152, or 252 as you can tell from the engine compartment.
But its tube spark plug head engine that might have been painted red before getting the blue so could have been original. Didn't think to look for a number on it before giving it to the guy who bought my '68 with knocking rod bearings.
Point of all that is I can't be too sure when the A/C went on.
The torxlike screw heads suggest it might not have been right away. Torx was just being introduced around then. There might have been other star drives though.

The factory "kits" Had everything except the R-12. I had to supply that. When done, you could not tell the difference, from factory installed, unless you were an expert.
The imports were the easiest to do, and as far as I know, every brand had the factory kit. Mopar and Ford had dealer installed kits available, but some were a real bear to install. I never saw a GM factory/dealer kit. So I am under the impression Gm never made a "kit". However, the aftermarket had just about every GM vehicle covered.