I bought the compressor. It is old, and it looks to me like someone threw on an old motor and took the compressor from an OLD thermo king refrigeration unit and turned it into an air compressor.
The numbers "1951" are stamped on a tag on the tank (as well as the max pressure, temp, etc) which leads me to believe the tank may very well be from 1951. It is in good shape, just dirty but appears to be very solid.
The motor is also very 40s or 50s looking, an old ugly 2hp 220v general electric motor, so old it has some kind of port for oil to go in for the bearings. It actually had oil dripping out of it from when i moved it.
The compressor says thermo king on it at the bottom around the oil sight glass and it says at the very very bottom "Use Freon Only". Thermo king doesnt make air compressors, that plus the fact that it says "use freon only" on it tells me it was a refrigeration compressor originally.
This stuff is fine, i don't need it I have my own pump and i have a gasoline engine i want to use it with. I will need an electric PTO clutch on the gas engine or head unloaders and related devices added to the pump to make it suitable for constant run situations. But I think the tank alone was well worth the $100. I only paid $180 for my Saylor Beall 705 pump on eBay. 17.3 cfm @ 175 psi and only 850 rpm.
I also have an 11hp Honda engine that i want to use for this pump that i have maybe $150 in. So all in all i'll have $800 at the most in the compressor. I'm not sure how good of a deal i got myself into considering the specs it will have (80 gal, 17.3cfm @ 175 psi) and my cost. I really dont have the capability of running a 5hp electric motor (compressor will be on a mobile equipment trailer anyways and i dont have a generator that is capable of STARTING such a big motor.) So 800 for a gas powered 80 gal 17 cfm compressor probably isnt too bad.