I certainly don't know. I've seen that gun a number of times and it's a fine piece.
About the one and only stickler it has is that at some point, no doubt in its years of use, someone filed a rear sight dovetail into the barrel, right through the letters Be of the name Beck. They show a picture of that on the auction site, and they should show that, although the gun is undoubtedly a JP Beck.
Strange too, is that some of the other items sold for well above estimate, like the Abner Howe musket, with a replaced lock. And the lock, a replacement that some could argue is not the correct style. None the less, it went for well above the high estimate.
I watched the auction, but didn't add up the winners and the losers. I know though, that if I was going to sell, I don't think I would use an on-line only venue like that....
John