@dartnlo Here are some more photos showing the original poti post. It's actually two pieces, originally for tone adjustment and volume. It'll only be on/ off and volume, but I want to make sure the other is still able to turn independently. I think I know how I'll do it. I'll cut down the post to the length I need while leaving like an extra 5/16" (that's how deep the slot is) and file that down to where it fits in the slot of the amp poti and epoxy that in there. I'll use part of that sleeve to wrap around it. Unless someone pulls on the knob with force it should stay in there. That way I don't have to buy anything and I'm making sure everything fits.