John K Jordan
Pictures, in case yours is different:
With a 3/8" Thompson spindle gouge
These are the two brass "buttons" I have for mine. The one on the left shaped like an inverted hat came with the jig. It works with the 3/8" gouge.
I bought the one shaped like a disk from Glenn Lucas a couple of years ago. It will NOT work with the 3/8" gouge. I think it is intended for big bowl gouges.
If yours connects to the threaded clamping shaft the same way as these it would be easy to make a custom one a little longer that what you have on a metal lathe or even on a wood lathe. A tiny o-ring holds the pin in a hole in the bottom of the threaded clamp. Or just slide in a shim, over or under the tool.