Very true, NHSteve, but this is one of the new upgrades Yamaha put out to correct that flaw. The old ones did not have the recess in the gear face, the clip/spring was not as beefy, and the eared part you point out is thicker and more firmly attached (welded?) to the axle here. Was a drop in replacement.
I have found a couple cheap on ebay and bought them anticipating perhaps needing them in the future, since I have 5 AT's and 3 CT's.

Good to know mothers, as I have a '65 YM1 waiting in the wings for some attention, although it doesn't have that particular issue, as I bought it as a runner.

I recall that the shop I worked at had an ace welder available, and when we would get a 125/175 with the dreaded 'kickstarter slip', we would take the shaft assembly out, clean it up real good, and he would do a little hard-face welding at the needed area, and we could put it right back in service. The customer could replace it, or we could weld it. Either way we could get it back in service quickly.

Keep us in the loop as to your solution? 

Umm, story looks to have gone from a 305 twin to the 125-175 trail singles. Maybe i'm behind on the story but none of the kick start parts would be in the ball park for the 305 sorry looking at the parts link.

My old manual must be packed away someplace...  but yes, YM and AT/CT kick starts aren't the same.