Francotte also made OU's using a Merkel-like system. Likewise, Abercrombie & Fitch imported a Merkel-like OU in the 30's. And there was a Charles Daly branded, Belgian-made OU (probably by Masquelier) also imported in the 30's--yet another Belgian look-alike. I've owned both Francotte and Charles Daly versions. They look similar to the gun in the above photo, but with more engraving.