Omron switch. Not switches, just one Omron switch in the whole mouse.
YSA for the three side buttons, Omron left click, Huano for right slick, and Boue(?) for scroll.
On another note, I think I fixed the tracking issues I was having with the Standard Issue. Pretty much wrecked the corners of the teflon pads, but at least the tracking isn’t all jittery now.