Excellent machines, built to last, absolute quality Lincoln built in America
Im sure the OP knows this but for others the red Lincoln Dial Arc is a really good stick welder, perfect for small shops, its single phase and I was looking for a used one not long ago.
The SA 200 is a icon and I currently have one im rebuilding
The last one is a motor generator, when they say heavy duty, this is the machine, I've used then in heavy industrial and shipyards, run forever, a true testament to a time when we made the best
My buddy had one, it was very old and he wound up scraping it. They are three phase, weigh a ton
The electric motor turns the generator and I believe like the SA 200 they only generate DC
Ive see them powered by gas engines.
I believe the Dial Arc was the next stick machine Lincoln sold over the legendary buzz box "tombstone" machine they sold. There are a lot of them around for sale at good prices. I never TIG welded with one but id think they would be a good machine to TIG with.....I think they are AC also so maybe if a high frequency box was found, might be good for alum as well