Nice to know you're back safely! :)
Lincoln has manuals available for free download here.
I have an old Lincoln tombstone that you change the voltage by
unplugging the cables and plugging them back into a different hole.
Tag says it's a 1936. Has a 6V battery charger built in too.
Yes, those handles are knurled metal.
Manual suggests turning it off before unplugging them. ;)
I also have a newer, AC only tombstone with a fancy switch.
Both of them are wired with 8 GA wire. I'd have to check for sure,
but I think they are on 40 amp breakers. I can check tomorrow,
but I'm fairly certain they are not more than that or I would
have used larger wire.