I doubt that anyone could say anything that would sway this guys opinion. After all, he's a Professional, and well, we're just guys on an internet forum.....
But, from what I see with my non-professional eye and from the small low quality picture they show, I see a commercial percussion lock style that wasn't invented until the percussion era, say 1830ish.
As for the swivel breech mechanism, it has an oval shape that does not follow the contour of the barrels like an early swivel works would have.
Also, the latch to unlock and turn the barrels is a lever ahead of the trigger guard, instead of incorporated into the forward part of the trigger guard as you'd expect to see on an early gun.
Also, there is no sign that there has ever been any forearm wood along the length of the barrels, nor any provision for, or a remaining forward part of the lock plate that would have held the flintlock frizzen and spring.
From the picture, it is obvious that the bow on the trigger guard is narrow, and the grip rail arched up into a nice curved shape.
Also from the picture, it looks like the toe of the butt is very narrow, and that would suggest that the butt itself is very narrow as well, say an inch to an inch and a half, certainly nowhere near two inches.
And from the picture, the wood strip showing between the door and the side plates of the patchbox would be very unusual on a Rev War period gun, but common on a late period gun.
Taking the above items that I see in this single picture, I see a late period rifle, made more or less between 1830s, to even 1850s or later.
None of what I see matches what you would expect to see on an early or Rev War rifle, but fits perfectly on a late period swivel breech rifle.
As Dick suggested, compare this gun to the Wm Antes Swivel rifle.
Of course there are always exceptions to the rule, but stretching this rifle back to the Rev War period is more or less impossible.
No, on second thought, it’s totally impossible!
John
