Well Flip (Hi Cobra) got a good used T-5 and is back on the road, now I have the trans and am investigating the problem:
At this point it looks to me like the 5th gear shift 'pivot' point on the shift rail is the culprit! It's very loose, woobles around and tends to 'bind' when your trying to shift into reverse. That shift rail IS 5th and Reverse gear! The case itself is also worn allowing the shift rail to move around, but I don't think thats contributing much to the problem, all though it may in the future.
At this point this is just a working THEORY subject to further exploration and ideas, input welcome.
By the way, while reverse idler gear teeth are showing wear I wouldn't say it's a 'bad gear'. The wear seems fairly typical of what you would see on a 'straight cut teeth' no synchro type of engagement gear. Shift rail movement in the case is present, but not severe.
