One of the guys in the body shop helped me out today...he screwed an implement nut onto the stud, tapered side first, flush with the end of the stud, then welded it, heating up the stud in the process. Then we put a socket with a breaker bar with a 3' pipe on it and worked it loose. Then I ground the weld off the top of the nut/stud, seperated them, and was able to repeat the process for the other side. Then I ground the new weld off, seperated the nut from the stud, and actually did no damage to either stud OR the nut!! Well...the nut is missing a bit of thickness, but it was plenty thick and I dressed the edges so it looks just fine!
So now I can finally mount the mower (with BOLTS!). I also got the grill painted as well as the hood, so they are ready to go on tomorrow also. Next step is to haul the tractor out to the farm and tackle some of this grass!!!
Thanks all SO much for your input!!