Meet my survivor
I see the tag is missing from the tranny case, but you are pretty sure it is the original COM. If you can, take a good look at the tranny case and write down, or take good pictures of any inscriptions you see anywhere on the case. There should be some stamped codes on it that will also tell you what tranny that is. If you do that post the codes here.
If you go looking for a tranny for parts, try and find one that does have the tag on the case still, and make sure it says PCE.