Originally Posted By: claycrusher1900

The barrels do appear to touch,


Higher grade English guns sometimes had flats spots in-between them where the barrels touched. A dead give away for me would be an odd barrel length (29 & 3/4") like you stated.

As you noted a section of the under rib has been repaired....I suspect it was repaired when they cut the barrels off account of some kind of damage.