hi jsup, do you still have your C4? met you at DC. i was going to say it is a 50/50 crap shoot even if it does run. but aftering pondering your question between commercials i don't think i would touch it with a 10 foot pole, here's why:
is that a rivited air tank in those pics?? i have never seen one and i have been working in shops with compressors since the late 60s, and they had old compressors at that time. rust inside the tank will cause it to rupture and you will have a bad day. the pump looks like it needs a rebuild (it looks rusty/crusty) can you even find parts to do a rebuild?? what condition is the motor in??? who knows. i wouldn't take a chance on blowing myself up with that thing. there is nothing in the pics to give it scale, but from the electrics it looks kind of small.
i bought a 60 gal. campbell-hausfield upright compressor about 5 years ago new with a cast iron pump,it was $399. i use it about 5 days a week, it has been trouble free and will drive everything (including my bead blaster and sandblaster). i drain the water out of the tank regulary. i know its history, who knows the history of that compressor. pass on it unless you are looking for a novelty item to put in a corner of your garage for display (then i'd offer $25) but as a working compressor-->FORGET IT..