Need A833 advice

I pulled the transmission last weekend, pulled the mainshaft, removed the rear bearing, and checked everything. All looked OK, but it was easy to reproduce the 'locking' behavior by hand. I experimented with several used brass synchro rings, and found the one that grabbed properly, but didn't lock up. The gear, replacement synchro, and bearing are back on the mainshaft and the problem behavior appears to be gone. (We'll know more after driving it a bit!) I also double-checked and re-greased the synchro assemblies and all was/is well.