25 yr. old unit not cooling
 

With outside unit clean and ner filter, our system doesn't cool, but does run. I'm thinking its R-12. What are my options? Anybody have experience with alcohol coolant?

Being that old chances are that it is an R-12 system which R-12 is hard to come by and if you can find it, it's very expensive. I would assume your options are to retro the old system to 134-A or just replace the entire unit. You may be able to get a tax credit depending on the particulars govt. tax credit and efficiency of the replacement unit. I don't believe residential systems have a low pressure cutout so it's basically running itself into the ground and will eventually cut out all together from internal over temp.