I do have a soft spot for the 122, it was the first cub I drove and I spent a lot of time on it. It's easyer for me with the low tunnel on the 72 plus it's hard to beat the QT.
The neighbor calls and says he's having a hard time adjusting the pto engagement. I go have a look and there's no wear button and the thrust button is toast. This is on his 129 I just sold him. The thrust button has been heated and the lip bent over to where it clamped on the three levers. I had to work them a little to get them out. It looks like a thrust button for the brake style but it wasn't before it became steel to steel.
It's all good now. I just thought it was an interesting little problem. It was a first for me.
Wayne, yep, that's what happens when the fiber button disappears. It may have broke it off if he installed or removed the PTO belt and didn't do it carefully. That's the main reason the brass button is better than the fiber button.