Re: check out my kegerator
Best replacement I've found for R12 is a mixture of propane and isobutane. I forget the exact ratio, but 1 can of coleman propane, and 1 can of the red mountain stove fuel comes out perfect. Mix is called C-12
It works at about 90%, and doesn't leak near as much as Freon. I've resurrected some pretty old vintage automotive systems with it.
For those who worry about the flammability, consider 1 lb of propane in a system designed for a couple hundred PSI of pressure, vs 150 or 200 lbs of gasoline in a plastic tank a foot off the road.
John