Referring to the Masquelier/Daly tie-in, Zutz wrote:

"Some of the Masquelier guns, both side by side and over and unders, were handled by various American importers during the pre-WWII era. One of these was the well-known Charles Daly, who, roughly between 1933 and 1939, handled an over and under made by Masquelier and sold Stateside as the "Commander" style . . . The Commander vertical doubles had a rather mongrelized assembly. Their barrels were made by Neumann, which was another smaller Belgian house. When they were sold with single triggers, the triggers were generally installed in the U.S. by Miller." Not that Zutz couldn't be wrong, but the Neumann barrels may explain the absence of the Masquelier proprietary trademark.

As for the Merkel tie-in, both Chief's photos and the photo accompanying the above-referenced Zutz article show a system which is clearly NOT Kersten. Quite different from what's seen on Merkels. The Kersten barrel extensions can be seen when you look down on the receiver from the top, with the gun closed. The barrel extensions shown in the Zutz article on Masquelier, and in Chief's photo above, are clearly "hidden" when the gun is closed. Also, Kersten barrel extensions are pierced to accept a crossbolt. On the guns in both photos--Chief's and Zutz's--the crossbolt lies across the top of the barrel extensions rather than going through them. An excellent photo of a Kersten, clearly illustrating its differences from the guns in Chief's and Zutz's photos, can be found on p. 78 of Zutz's book, "The Double Shotgun". Or for that matter, you can just look at any Merkel OU.