[hbueno]

To be clear, the hissing sound was not a leak. It sounded more like the expansion valve doing it's work.

I have the records for the car dating back to late 80's, and can't find anything related to A/C work, so there's a good chance it is/was still running on the original charge.

I'll do some testing to try to confirm if it's low refrigerant. If yes, I may still pursue the R12 route.

Hugo