The Williams of Williams Gun Sight Co. was not, as far as I know, connected in any way with David Marshall "Carbine" Williams. They are still in business:
I once got called down on another site for saying that soldiers generally called the WWII rifle the "M1" rather than the "Garand". The other poster called me several kinds of names and questioned my intelligence, sanity and ancestry. So if one must cater to those folks and call the M1 rifle a "Garand", why not call the M1 carbine a "Williams"?