[kidatheart]

I am by no means an expert body man but I made a good living at it for 25 years. My first thought is that it would be much easier to unchop a top than to chop one!
If you have good doors around, that takes care of that issue. Glass wouldn’t be much of a problem. Cut the chopped top low on the windshield posts. And cut the back of the cab below where they did their work. Take lots of measurements from the donor cab and use a die grinder to make some marks for reference points that won’t rub off. Tack it together and make sure the front and back glass openings are right, fit the doors, weld it up. Myself, I wouldn’t want to mess with changing the cab because if VIN issues. I think it sounds kinda fun and interesting. Good luck and keep us posted.