I was also looking into this and none of my options were any good. I asked Corey's Auto in Cumming to get me an estimate on how much it would cost to convert to r-134a and after running some tests, it turns out my something in the system, probably the AC compressor, is no good. They had some r-12 and gave it a partial charge and it just leaked right out. To have it working again and charged with 12 or converted and charged with 134a would cost more than the car itself.

This has been a looong summer. Stubborn crank windows and no AC.