73 / 17 is the teeth on the gear, the larger putter gear has 73 teeth and the smaller inner gear has 17 teeth.
I bought one that somehow has 74/17 and doesn't fit the bike but is identical in every way. The bike I have is a 93 I believe. If you'd like to sell it, please let me know. I think it should fit.
I contacted a manufacturer about the clutch basket and can have them made, but it would be quite a few, not sure if anyone would want to be in on an order of a few dozen or a 100 or so. I'm in a bind and need one (3 really) thought about seeing if anyone would want some and get some pricing on some units so we could have some. Just a thought.