128 lift handle detent pin/ button help

[Steveshow]

I have a 1973 128 that was passed down to me by my dad. He got it from my uncle, his brother. I believe he bought it new. It came with a tiller attachment, but the story always was that it was never used, as the ground speed of the tractor was too fast, and it was too heavy to lift. (The paint wasn't even worn off the tines when I reinstalled it!) I sure wish he would have bought a 129 hydro with electric lift...With guidance from this site a couple of years ago, I sourced and installed a creeper box and a lift spring assist. Now I nee help disassembling the lift arm, as the pin/ button that extends out of the handle has been broken off for as long as I can remember. We used a stubby screwdriver inserted from the top to engage the detent in order to raise and lower the mower deck, but that set up gets a little complicated with the heavier tiller. I bought a new pin, but before I go ham fisted tearing into the handle, I thought I would ask for some guidance.

[Steveshow]

I found a spare lift arm (I guess that is what it's called...) It's the chrome hollow handle mounted on the right side of the tractor that's used to leverage the lift up and down. It has a 1/4" rod that runs down to the lift assembly. It has an inch or so long rod welded onto the end where it interfaces with the lift assembly. The new "button" I bought screws on top and sticks out in order for the user to unlock and lock the lift in place. It appears that there is a roll pin holding the hollow steel lift arm. I put all of the parts I had together and understand it's operation now. The only piece missing is the "float" button on the shaft that is activated with the operator's index finger. The existing handle on the tractor had the button, and it was functioning, so I tried removing it. I sprayed it with PB blaster, but since the handle is still on (spring return) the tractor, in a vertical position, I don't think much made its way in. I took some small vice grips to it and got it out, but at the expense of damaging it. It now now longer returns smoothly... I guess I crimped it when I removed it. Knowing what I know now, I should have left it in the arm mounted on the tractor and repaired it instead. Hindsight being 20/20 and all...Does anyone have a spare button or know where to source one?

[R Bedell]

Here is the Lift Mechanism per the Parts Manual. Which part are you referencing?

[Steveshow]

#8 in the illustration. I found one online ($17!) but i haven't installed it yet.

[finsruskw]

Number 8 is the spring retainer washer.
Keeps the spring from falling down inside the tube

The release lock ass'y is what you need and it is not pictured
Part #IH-401449-R1 is what you need.
It is listed as part of the lift handle ass'y