I believe that there were two maker's of the Derby, one being Zabala Hermanos. I think that ZH may have been the second company to make the guns for American Arms. From an earlier thread (if I remember properly) the ZH gun's engraving was roll stamped. I ran into a 12 ga recently, with the single trigger. Pics of the barrel and action flats will tell the maker, as well as the year proofed. I'm sure Kyrie will know the other company, I think he provided the info that I'm repeating.

here's the link for the Maker's Marks and date codes.

http://www.shotgunworld.com/bbs/viewtopic.php?f=126&t=160159

Regards
Ken

Last edited by Ken61; 12/18/14 02:37 PM.
I prefer wood to plastic, leather to nylon, waxed cotton to Gore-Tex, and split bamboo to graphite.