Joe - I know a guy with two 40’s, both 91MY, VIN range 6354xx to 6466xx and both of those cars have the same connectors as ours, regular threaded fittings.
Robin’s car had the same too, right?
All I can think of is that they were introduced for a short while somewhere in the middle of things, maybe late 92-early 93? I know Ford used them quite a bit so maybe that had something to do with it?
My plan (if I couldn’t use the spare) was to try and repair it using the stuff A/C techs use, “LA-CO Heatstik”. My attempts at aluminum welding the condenser were miserable failures but when I discovered this stuff I successfully fixed the condenser and to this day have nice cold A/C.
LA-CO is heat activated epoxy with a 60 second cure time. You clean the area of the leak to bare shiny metal, heat it up the damage and just puddle it on.
When I fixed my condenser with it, I decided to reinforce it (it is a bit brittle) by coating it with a layer of JB weld. I just roughed up the LA-CO with some sandpaper and put a blob of JB over the whole area, Five years later, A/C still good.