Hey! Thanks for continuing to post questions on the forum. For sure we want to keep things going in here as many folks are posting as well on our FB page.
This problem is almost on every 780 given age. The fix is rather extensive and does require the leather to be pulled up a bit to get to the motors. One side turns and the other is stripped. Here is the best video I’ve found on fixing… https://www.youtube.com/watch?v=lGITgKXCBbg