how cheap is it????
I worked at a place repairing tools for some time, a little while back. I didn't have the job long enough to know model numbers and whatnot off the top of my head, but I know that ALOT of chinese knockoffs (at least air tools) use parts IDENTICAL to the quality versions that they are copied from. I also know that the wire feed motor is VERY VERY easy to replace. It MIGHT be worth it to take the wire feed motor off of the welder, take it in to a local repair shop, and see if they can match it up with something for you.
Personally, I used fiberglass to repair my passenger floorboard in my Datsun. There were holes in the floorboard big enough, that a 5 D-cell Mag-Lite just.. disappeared from the car

(it lived in the passenger floorboard, so it must have dropped out somewhere. Maybe thats how they filmed that ad of the semi running over the maglite?

) I cut the entire rusty bit out, treated the metal margins that I left, and laid down about three layers of fiberglass cloth. If the car were large enough to stand in, you could jump up and down on my new floor. I can see where many might not care to do this, but it worked great for me, so I thought I would pass the idea on.
(oh, and I just meant that I was suggesting an idea, in case you hadn't thought of it

NOBODY likes their floorpans flying off when they hit the throttle in a bottle:Flame: )