Need help, underhammer rifle

[Commodore Swab]

If this is the wrong place feel free to move. I have acquired a batch of parts to build a triple barrel (2 rifle, 1 smooth) with the lower being a custom underhammer flint. Any literature or pictures involving the frizzen/pan and stock fitment for the lower lock would be of assistance for inspiration.

 

[BruceHH]

Now that is an interesting task you are taking on. Good luck with the project.

 

[russellshaffer]

Do a search for underhammer flintlock. There are quite a few pictures that might give some ideas. I found this auction link.
https://www.historicalarms.com/antique-guns-swords-artifacts-for-sale/4930.html

 

[Rifleman1776]

Love to see pics of your three barrel gun.

 

[Commodore Swab]

It's not much more than an incomplete pile of parts now. The parts employ a folding trigger for the lower barrel like a box lock. Unfortunately there is a long sear to engage the **** and I have been unable to figure out what would trip it to pop out.