I love my G600 as well.

I think I nearly know how to replace most of the mouse.

I can resolder new switches, mouse-wheel button and those buttons below the mouse wheel.

And replacement pads for the mouse feet are easy to buy, if not, you can buy a pad uncut and custom-cut it.

I just now need to learn how to replace the side dome buttons individually instead of replacing the whole PCB, since I cannot keep buying replacement mouses for just those side mouse buttons as the price seems to be creeping up with the increasing scarcity.