Bobcat 720 and 721 projects

[eric67camino]

Howdy. New guy here. I've tried searching, but have that just created more questions. I have a Bobcat 720 that I bought earlier this year. (Hell of a trip going to get it.) It was in rough shape and has been sitting a while. I got it running, added oil, bled the system as best I could. When I tried to drive the right side moved and the left did not. Not enough movement from the left lever. About that time the seal at the engine side of the pump blew out. I tore down the pump and it looks like someone threw a grenade in the left steer side. Due to the situation with the 720, I was looking around and found a 721 for cheap. (Also an adventure of a trip. Hmm, I wonder if that's a sign.) Its in better shape than my 720 and the guy was running it when it quit on him. Believe the crank is broken because the starter turns the flywheel, but the front pulley doesn't turn. My understanding is that these are the same machine, just with different engines. I'm some kind of mechanic in real life, but not super familiar with skidsteers or diesels. Here's my questions: 1.) Would it be cost effective/worth trying to fix the 721's diesel? 2.) Will the 720's Wisconsin bolt in in place of the 721's diesel? 2.a) If the crank is different, can a just use the cv shaft from the 720 to adapt to the 721 pump? 2.b) If that works, does the pump turn the same way? I thought I read in my searching that the diesel runs backwards compared to the 720. 2.c) If the pump runs backwards, can I just swap the end pump from the 720 onto the 721 pump to fix that? Thanks in advance for any help. I know these girls are old and info seems to be sparse.