Shinn Thanks for the ebay link. I also opened it to check. Side small buttons ( same as middle button ) measures 5.2mmx5.2mm footprint is about 2.5mm spacing in center, 4.5mm outter edge to outer edge, actuating height unpushed is 1.5mm. The ebay link doensn't provide part number but digikey has close approximations just a general description as ALPS Mini Push Button. Search shows it might be a ALPS SKQGABE010 which shows 5.2x5.2x1.5mm 160gf. I think those are it ! THANKS for the help.

Tons of posts about the main front switches. Zero articles about the side switch and their part numbers. :(