Welding

Hello all, any welding fanatics on here?. I'm sure there is, some members on here know I lost my father yeeeears ago and I acquired all his equipment. I have a Hobart Handler 120. I don't use gas with it. I use it for art projects or minor repairs around the house. I don't not have the manual for it but just recently downloaded it. The issue I'm having is that it's feeding way too fast, and the feed dial "sometimes" works when you turn it down, but majority of the time it's on 8 on up. I've searched high and low but parts for this unit are obsolete. What research I've done is the rheostat dial could be bad, would it be possible to use another dial from another brand of welder??? I really don't know much about servicing this unit. Anyone in Texas or the Houston area know a shop?.