So i picked up this old Craftsman AC/DC welder a while back, no leads, working status unknown.
Pulled the cover off and omg, she had solid 4 inches of dirt, sawdust, cobwebs on the bottom of it. Vacuumed it all out, scrubbed off as much dust as I could.
Ordered new lead wires (#2AWG), new lead connectors (Lenco UP-10), new ground clamp and electrode holder (Tweco GC-300, A-316)
Got the leads all put together. Put the correct plug on the power cable (it had a dryer cable/plug on it), i believe it's a 10AWG, will be upgrading that asap to at least a 6AWG even though the label on the back says to use 8AWG.
Turned it on and she's alive! burned a few rods of various sizes and it seems to be doing ok.
My question is: this is a 230V welder capable of running on 208V and 230V, currently wired for 230V. I took a multi-meter and tested my outlet and on each side it reads ~124V
So, with 2x124V wouldn't it make it 248V? Is it still safe to run this welder as is or do i need to do something different?

You're fine, most voltmeters aren't too precise. 208 is 3 phase wiring which you don't need to worry about. 230 is from when they used to refer to standard line voltage as 115VAC, so you would get 230 if you pulled off both sides of the breaker box/meter. Nowdays they use anything from 110 to 120 to refer to line voltage. Most commonly 120, so double that and you're at 240VAC, within the tolerances of your meter +/-.

Pretty cool you have it running. Probably should have it on a minimum of 30 amp breaker. 40 would be better. See what it calls for on the spec plate.

i have a 60 amp breaker on this outlet
here is the tag from the front of the machine

You're good to go. Just don't be like me. I don't think I've ever welded anything without setting something on fire!

Like your shirt sleeves? I have a couple of shirts with burn holes.

Shirts, pants, shoes, socks, gloves, workbench, vise.........I turn into a pyroclusterfuk with an electrode in my hand!