Well had to strip my pad, someone had spilled something on it and while I was in it I noticed these
They look like contact pads for 0603 smd LEDs ,which I then looked at the ouya home button which is where I found another problem its not transparent at all
So I have a few ps3 pads laying around
And test fitted a ps x o tri square button
Which I found too small to be comfortable with

So I thought I'll try thumbsticks ....and they do fit but require a small spacer in the thumb sticks they sink to far down ...d pad no way either

The o,u,y,a buttons are smaller than square,o,tri,x on ps so no luck there
I don't have any 360 pads so can't test any parts but maybe worth a try if you do