Is there any gap between the barrels at the muzzle. Usually uncut barrels touch. Also, are there any steel "keels" at the muzzle in the little "V" formed from the top rib downward to where the barrels touch? Or is it just filled with solder? Is the front bead dead center the rib? All these are hints to look for.

Yes, it sounds very likely the barrels have been honed, perhaps significantly. However, cylinder bores were most common in the time you have given for manufacture.

When an old man dies a library burns to the ground. (Old African proverb)