You win some and you lose some. On eBay, I scored an old AC/DC Idealarc 250 (the kind with the round corners, not the current rectangular model). The adjustment crank turns very smoothly. The power switch sounds fine. The polarity switch is a little tight, but seems to work. Surprisingly, Lincoln has the manual on their web page. It gives instructions for lubricating the crank. I'm going to remove the cover this weekend and do that. Is there anything else I should do while I'm inside? I'll blow it out and try to clean the fan as well. Should I try to clean the switches?
The data plate says 208V, which is good because that's what I have. If later on I decide to run it on 230V would that cause any problems?
Oh, by the way, I also scored a giant welding table.