Considering 82 300D

I am considering the purchase of a 1982 300D and have a few concerns. The owner says the AC compressor bracket broke and the compressor fell off. He then took the hoses loose, releasing all the r12, and put the compressor in the trunk. Questions: What would cause the bracket to break? Motor mounts, seizure, just loose bolts? Now that the system has moisture in it, what should be done to get it back in serivce? Replace drier, valve, compressor? Is this the Delco r4?
On another note, the owner says it's not a turbo. I thought all of the 82's were turbocharged. Did any of the 82's come without turbos, maybe he is just not aware of the turbo? I hope it was not removed as well!
The price is pretty good on this one, so a little work is ok. Has new calipers, alternator and battery. I just want a commuter car that's safe and gets decent fuel mileage. Any info will be greatly appreciated.