An ebay commando stuck me with several of the Chicom pinions which I mistakenly believed to be real US GI components.These are unusable with the US GI M1 Garand rear sight base because the OD of the pinion shaft is too large to enter the base.Has anyone found the complete Chicom rear sight assembly(base,pinion,aperture,windage knob) to function OK on a Garand receiver? As I understand it the Chicom stuff is made to a metric spec whereas the US GI obviously was not.