Rivets, I just went to a local parts place here, gave them the numbers I had, they looked it up and said to use Model #20594. and they considered it a Pony III. Link is below, go to owners section, enter that model number and you can get the owners manual and the parts manual. I just got 'em and it looks like the right stuff..............
They didn't understand why Troy Bilt tech people couldn't have come up with that......... Who knows???
Lawn Care Products: Lawn Care Equipment from Troy-Biltョ