Independence day (weekend) update:
OK, time to weld the frame back together. The first thing was to make sure that we had the right electrode for the wire welder. The 89 FSM had the specs so I went and checked what we had in the MIG. Turns out it was what we needed. I'll leave the welding theory to others but basically the difference between the 3 and the 6 at the end of the spec was new metal vs. old metal and mine is 30 years old