Actually those are 24mm, hence the "24" in the name. Those are the buttons that are used for start and select on Madcatz TE sticks. They are way smaller than the normal face buttons, and would not work well in place of the normal 30mm buttons.fastbilly1 wrote:Sanwa OSBF-24 buttons should be 28mm
As for fitting in 30mm buttons, its not that much modifying to the panel to fit in the 30mm, I had to do it to my Neo Geo panel because I wanted Sanwas instead of HAPP style (which are 28mm). It was like 10 seconds of dremeling the hole with the grinder bit and they fit like a charm.
Edit:
Look at this auction, and check the pic, the smaller buttons are the same 24mm ones being talked about, the 3mm below them are close to the ones already in the stick you have. They are way smaller, and would not even snap in, but just sit loose in the hole.