Posted by Norm on September 14, 2015, 8:17 pm, in reply to "General Information"
Your dad's O grade was made in 1896, per the dare chart elsewhere on this site. London steel barrels became an option in 1907, so I'm guessing this set was added at a later date - which is not uncommon.
Were it me, I would be concerned about the short barrels, as I think barrels shorter than 18" are subject to the NFA. Might want to tread lightly until you find out for sure.