Hey Scottly, welcome to my thread. How are your hand cut dogs holding up after all this time? Reading your posts when I first encountered this problem had me warming up the dremel.
They are actually holding up quite well, but then I don't ride quite as hard as I did 30 years ago.
Make sure you install the snap-rings properly. One side has a slightly rounded edge, and the other side has a sharp edge. The side with the rounded edge HAS to go against the gear, or the ring can be pushed out of it's groove.