Looking at the second picture of the brass ring posted it appears to show wear marks on the outer surface of the ring. I am referring to the surface that actually faces the gear. At this point I would check ,as jwb123 pointed out, how the rings actually fit and grab the gears. If they go on too far and bottom out against the integral synchro teeth on the gear, its not good. The bottom picture has those scuff marks that give the impression of that surface coming in contact with another at some point. It never should. I also realize it is a photo and that may just be a glare that I am seeing at my point of view. If they are in fact grind marks (radial) you would need to establish how they got there. It suggests interference of some kind. I do not have any personal experience with dual disc clutches,but it would seem that those discs may act as 2 big flywheels wanting to stay in motion ,when the clutch is trying to release, but keeping that input shaft in rotation. I hope you find a solution to this issue. Bill