I'm interested, Greg - my 5U idlers are terrible. Can you send a parts list and I'll see if they're going to work for mine. I may swap out the entire idler wheels as at least one of mine is so worn out it might be a challenge to build it back up.
Neil- look at the ad I just posted in classifieds, with part numbers. Don't know if my 4U parts will work on your 5U.
Greg