The old barrel loop scar a few inched past your current breech plug pretty much tells the story. At 37 inches, the barrel was probably about 43 to 44 inches when new. It would have been cut about an inch at the original muzzle to remove the old front sight and to provide a clean, new surface for the new/current breech plug. The old barrel was then shortened another 5 or 6 inches at the old breech to reach today's 37 inches. Since they had cut so much off the old breech, and lost most of the swamping at that end, they flipped the barrel so the old muzzle swamping was now at the new breech to put the heavier/wider end of the barrel at that end, presumably for more strength at the breech where the charge explodes. Shelby Gallien