OK. So I have successfully installed Sanwa JLF-TP-8T sticks into my old CPS2 cabinet (which has a 4 slot in it currently. These sticks are widely considered the best joysticks (especially for fighting games). As I stated before, they don't quite fit into american cabinets.
What I did was took 4 cotter pins from Home Depot, and used them to secure the stick in place by putting them on the control panels original bolts. Now, this alone is pretty good when we're trying to hold it in place, but I took an extra step. On the actual mounting plate, there are holes for the control panel bolts that would normally fit. Since they do not, I simply took some Super Glue, and filled the holes to give a bit more security.
Now, make sure you use NORMAL super glue. Not JB Weld, or something that you will never be able to remove. A little bit of super glue will make a strong hold, but you could still get it off if needed. Also, you are only dabbing a little bit in the bolt holes. The cotter pins are the main thing holding the stick in place, not the glue. The glue is just their to stop any shifting that would loosen the pins.
Is this retarded? You bet! Did it work? Hell yeah!
Now, the buttons are a bit more straight forward. American buttons holes are 1 1/8th" in diameter. Sanwa buttons are 30mm. 1 1/8th" in mm is about 28.5mm. So the holes need to be widened by about 1.5 mm. Just grind them with a Dremel and you're all set.
Forgive the crappy wiring, I'm still waiting for plastic wire nuts from Bob Roberts