I'd like to get clarification on one thing..

Did the case of the tranny actually split? Or did a mounting flange bust off in the wreck?

Most of the time, trans work isn't DIY. They can be a real pain to reassemble, plus I'm concerned over the integrity of the tranny given the damage it sustained.

I'd be pragmatic about it and replace the tranny [if the case has actually split or has a hole]