Well Robert, there's a good chance I'm wrong!
But, what I see is that the rear sight too far back. It usually sits about over the rear RR entry thimble.
To me, the signature looks too far back, about the same distance as the rear sight is too far back.
There is a witness mark on the forward end of the tang, that usually aligns with a witness mark on the back end of the barrel. Except there's no longer a witness mark on the barrel. This mark is engraved/cut as a straight line after the barrel and plug have been fitted, so if the plug is ever removed, it could be realigned exactly as it was originally. Since the line is cut in one motion so to say, on the fitted tang/ barrel unit, If the barrel was the original length the mark should be there.
And just by looking at the pictures, it looks like there is a longer distance between the rear ramrod pipe and the center one, than there is between the center pipe and the forward pipe. But the pictures are all angled a bit, so it's hard to say for sure.
And, if I remember correctly, a lot of Beyers barrels are usually about 45 or 46 inches.
It'd sure be easier to tell with gun in hand!
PS. Just saw No Golds reply, and he makes an equally good case for the barrel not being cutt back,,, well almost as good as mine.
John