When Bill Ball attempted to recharge the apparently original R12 system on my 85, we were perplexed to find an R134 type quick connect adapter on the low side connector. We were in a quandary because we didn't have any way to confirm that it was actually R12 in the system and not R134 (although we were 95% sure this was the case.) After a bit of head scratching we removed the adapter and discovered that the threads on the original outlet had been munged and instead of re-chasing them, whoever serviced the car had decided that adding the adapter was the right solution. Adding an appropriately labeled hose to the equation seems like a pretty good idea...

 

I just got mine back from an R-12 recharge at Schneider Autohous here in Santa Barbara. Yep, they still do R-12, they found a leak too.