the switches syntaur are selling look very close:
https://syntaur.com/Items/5232.html
i'm assuming the base dimensions and the height are right, and the bezel clips look like they could be right too, but it's hard to tell whether the bezel will fit around the top section and whether the button top will clip into it. i asked them (because they aren't selling the bezels or tops) but the guy was confused as to which parts i was talking about.
i've had a look on a few wholesale sites but getting the right dimensions feels like a shot in the dark. best bet i think is i'll order a couple of the syntaur buttons and see if they fit.. with a bit of luck they will.
it's all cosmetic and for fun in any event, i was considering just soldering some other momentary switches i have to a little PCB and making a hacked version to use the sequencer but i'm happy to wait and try to get a proper fit.