Ok, so its an AliExpress gear knob, 6 speed for the MYP. Gaiter, I think came with it. The TT ring was machined with a step to make it sit flush whilst clamping the gaiter, as the gaiter is thicker than the TT rubber bellows. Screws are 6 x 1/2" in old money, but 3.5 x 16 would be ok. Get Silver, not gold finish.