IIRC, there were 3 major outfits building high end adjustable sights for target use, King, Micro, and Triangle. You see virtually identical (mechanically) versions of all 3 on .45 hardball guns from the late pre-War period through about the '60s. As memory serves, King started first with a variety of sights back to the WW I period give or take, and Micro outlived Triangle by a little as the popularity of formal bulls eye shooting waned. If you look at the 3 side by side, you can see an awful lot of similarity, but it might be a matter of "form follows function." BTW, didn't Ruger use Micro sights on their adjustable sighted guns for a while until they started making their own??

Froggie