[Earthworm]

Depends how lazy they were. The R12 connectors look like tire valves and should only be on 92's that haven't been properly converted.

A conversion kit should come with new connectors that screw on to the old connectors as well as enough green o-rings to replace everything throughout the system.

Also be aware there are alternative gasses out there that claim to be compatible with both R12 and R134a.

Best bet would be to have an A/C expert check for leaks, vacuum and refill the system.