Thanks for these notices. Norm Flayderman owned this for years - it is the one that has been pictured in his Guide to Antique American Firearms as an example of Double Barrel Kentucky Rifles, so maybe the one at the NRA Museum is another one or Norm loaned it to them for a while. I cannot find my current American Rifleman magazine to look at the picture, but I will. And I will also see if I can find something on the internet about the Allagash Traders print that you have Hawken62 to see if maybe they borrowed a picture for the print that you have.
Some interesting things not noted before about this rifle: there is a Masonic compass and square engraved on the lock, there is a neat brass engraved inlay over the entire comb of the stock, the frizzens have been struck only once or twice and the rifled bore is very sharp at the muzzle. I am thinking that this might have been the maker's rifle, or I guess it could be one that he couldn't sell, but to me it is very uncommon that it would have been used so little. Had to have been an expensive rifle. The ramrod, with iron worm and horn tip I believe is original to this rifle.
I'll get some better pictures together and submit it for the Virtual Museum soon.