Got it back together today. Had to take the new wrong thread release slide that I was sent, cut it in half, and weld it to my old one to make a functional piece. Also had to add some weld to the tip of the thread release pin because it was worn down from so much use.
I'm now having an issue where part of my top thread is getting caught under the bobbin case. I can still sew fine (although top tension appears to be way too tight, even backed off all the way, bobbin tension seems to be good), until the end, when I lift the presser foot and try to pull my piece out. It's jammed in there, with 4 threads attached to the material and the machine, all a big mess.
I had timed the machine and adjusted the bobbin tension a few weeks ago, but this is the first time I use the machine with a motor. Anyone have any ideas? Timing off? Need to check it again.