Hello Cadillac Bill,
You have posted an interesting rifle that has gotten a lot of attention here. I'm hearing you out and have no interest in aiming at you ;-)
Many thoughts come to me regarding your fine acquisition which I want to share.
It certainly was flint when made for the many reasons given. Pukka Bundook mentioned 1780's or later. He is much more knowledgeable than I about European locks, but with the stirrup-connected main spring, I would have thought it dated into the 1800-1820 time frame. Maybe better informed readers will chime in. It certainly was made with two lock bolts. The lock molding relief for the cock arrest shoulder seems awfully shallow on the photos, and makes me wonder if the lock used the very late type of cock arrest using a reinforced lower jaw arresting on a heavily beefed up pan fence. Just speculation.
The names are hard to pin down. Herr in Der Neue Støckel lists many gunmakers named Blachon in St-Etienne, as well as numerous Montagny's there. None of them are paired together. Montagny is also a town nearby, but in his location index, Herr doesn't mention Montagny as a gunmaking center. The area is in eastern France to the west of Geneva, Switzerland. Tordu is French for "twisted". The lock name I see with difficulty, but looks like "Depri" to me, and the town I can't guess at. Any help? Herr lists 7 "Deprez's" in Liége, Belgium, but nothing closer to "Depri" that I can find. Are there other names or aspects that relate to it being a Swiss rifle?
The conversion impresses me, as do so many European conversions. The pan has been replaced with a nicely designed oversized fence to protect the shooter and wood from the cap detenations. The drum was screwed in as evidenced by the index marks on the bottom, and maybe soldered as well. It was shaped to fit the pan recess in the lock. The lock was made easily removable for cleaning off the corrosive cap residue after each shooting session. That is why the front lock bolt was replaced by the hook that was screwed into its threaded hole in the plate so that the lock could be removed easily using the single new thumb screw. The dummy front lock screw is strictly cosmetic to fill the hole left by the original flintlock front lock bolt. To me, this conversion was well thought out and executed for an early owner who loved that rifle as much as you do.
Now my thoughts on reconversion:To make "it to be like it was when it was born", many questions will have to be answered correctly. Should the cock be double throated (reinforced) or not? Might the original lock have been born with that late FL arrest system using the oversized lower jaw and fence? Should it have a roller frizzen or roller frizzen spring? Or maybe no roller? Are you willing to discard the thumb screw, remove the front lock hook, and probably remove the "figure 8" washer under the thumb screw, because it was probably put there (replacing the round washer that matched the one under the front lock bolt) when the thumb screw lock removal system was installed at the time of conversion? Was the rifle born with a vent liner? Even the most knowledgeable European rifle specialists will be guessing at answering these questions.
The previous European owner loved your rifle so much that he had her carefully and thoughtfully converted so he could proudly show her off to his friends and compete with her more successfully. He helped her successfully mature and keep up with the times. She can never be "original" again, no matter who guesses at how her reconversion should be done or how well it is accomplished.
In carefully choosing the best specialist on European rifle reconversion, you will certainly encounter a long waiting period. Use that waiting time to lovingly shoot your rifle, clean her easily using that wonderful converted thumb screw system, keep her on the wall with her original nipple in place (she is so much more beautiful that way), and bond with her more and more during your waiting period. You may become as impressed with her in her maturity as most of the rest of us in this thread already are.
So you see, no aiming or shooting, just a comrade in arms happily sharing the wonder of your rifle with you. Maybe you’ll even take her off the waiting list...
Bill Paton
Anchorage