Don't have any answers, for your questions,
but I found mine broken this past season, and the teeth were gone on the outside edge, just like your's is showing, never had any noise or
anything out of the ordinary, only mine had taken half the tooth off,the only way I found mine, I went to change the gear oil, and teeth were falling out everywhere.

Pattern looked good, quite as a mouse, never figured out why it happened, BUT the next set I put in I took my do-more grinder, and chamfered, the outside edges of the ring, and pinion.

I thought maybe with the sharp edges of the teeth,there was cause for stress risers, with the ring gear rolling in the pinion, just my thoughts,but when I changed the gear out to go to Rockingham, it looked super good, so who knows.

P.S thanks for the mag.

Dave