This is a modified version of the base and of the rode of the piston to make it an actual key for your keyboard. The idea is that only the “wood” part moves as if you were actioning the piston. The original cross in the rode was too small to fit my switches but it might come from my printing setting / filament so if it's to wide just use the original one (only the round part, keep the square one to have the same visual as in the game. 

I've included the F3D file in case the block doesnt fit your keyboard.