Dave,
Great Progress!. What did you use for barrels? I used a pair of barrels made by a custom barrel maker but he refused to make them with walls less than 0.075". This has resulted in a very heavy gun. If I ever make another I have to get barrels with appropriate wall thickness.
Dave's observations regarding locks are right on. My gun is French ca. 1740. I would have preferred to use the Chambers small Siler locks and modify them to "look French" but, alas, there is no left-hand version of that delightful little lock. I had to use the TRS #603 locks instead.
I have been side-lined on my gun while I got my PA house finished. But now I am finding some time, here and there to get my doublegun closer to the finish-line. It won't look as good as yours but it will be the best I can do.
Best Regards,
JMC
John Cholin