Are the rollers visibly out of round or warped? There isn't much to these contraptions, just two round pieces of metal held in bearings a fixed distance from one another. If the rollers are damaged, out of round or bent, you'll have to get new ones; otherwise, keep cleaning.
I'm not sure if the roller assembly is interchangeable between camera models, but I bet it is, given the production advantages of having one standard assembly. You might find a tired, old camera that has other problems and trade rollers. I may even have one. If I do, I'll send you a PM.
As for the tab position... I can't at the moment remember. As I recall, the pack pretty much sorts itself out when placed in the holder - no fiddling or inserting Tab A in Slot B required.