When I went to go buy my what can only be described as my sexy tractor lathe (my South Bend I'm restoring) he had a 48" Bridgeport mill he wanted for $450 or best offer, it's super rusty and as any knee mill weights a metric fuck ton of 1,800 lbs. I thought about buying it on the spot, but I currently don't have space in the barn. And my tractor cannot lift it, however he said he would load it into my truck and I have a relative that can store it for me while I work on it and my relative has a neighbor that has a soup'd up tractor that could unload it. So here the question, is it worth buying? It needs a lot of work and is super rusty, it does have a pump in the back compartment as well as the motor was swapped with a 110v motor that appears to have a lamp cord soldered on (which I would swap the motor out) and it has all the 3 phase switches and accessory except the handle for the knee. It would need a lot of work and would be at least a few months of work. Also on a finale note, the blue mill for the 50-60s is for sale for $2,500 at my work which should I save up for it or buy this rust bucket? Cheers!!
If the spindle was free turning and you could still make the handles turn, I'd maybe consider it, but that is in incredibly bad shape. It would need to be completely disassembled right down to the gearbox, have all the ways relapped and ideally re chrome-hardened (not for the layman to do), probably all the screws cleaned and potentially replaced because I'll bet that has a ton of backlash, belt replaced, everything re-leveled and squared. It is indeed a ton of work and if you don't know the tricks behind taking Bridgeports apart, don't have the additional equipment for the precision surface repair - or don't have a small jib crane around your shop to actually move all the insanely heavy parts - it's going to be quite a difficult, albeit not impossible, kind of job.
And all of the above is simply hoping that water has not collected and pitted the ways beyond repair.