I just sent an L&R lock back because the tumbler shaft stuck through the plate so far the cock stop was only hitting the edge of the plate. When I got the lock back I found they had scratched up my carefully polished lock plate. I disassembled the lock and found they had crammed the tumbler shaft through the lock plate with some force, the tumbler shaft had a huge burr on it from grinding the shaft shorter, they had forced the shaft through the hole, burr and all.
I thought, how did they scratch up my lock plate and how did they get that shaft into the plate with that huge burr on it. Now I know, they used the tool mentioned above, real shoddy work on their part.
I sanded and repolished the lock plate, filed off the burr and polished the tumbler shaft, all is well.