and know someone with a MIG welder you could weld it back on.
I've fixed a few things at work that were cast iron using 309 wire in a MIG welder. Here is a video that I followed when I wanted to try it.
I agree with Andrews assessment of the failure. With the end of the gear all burnt, it was definitely rubbing hard and caused the lock up/failure.
If the person that did the rebuild was only familiar with late model transmissions, I could see them not realizing that the gear was too tight(no side clearance). These boxes need SLOP to allow the grease to get in all the nooks/crannies. The new stuff is all run with ATF and is built TIGHT on clearances.
2006/2009 UMTR Points Champion