They're all unsafe, Mike. Sell them immediately. smile How many of those guns (other than the AyA) were made after 1930? By that time, we'd switched to higher pressure shells. Lengthening chambers AND shooting higher pressure loads might be a bad combination.

Eightbore, re your comment on British proof . . . the drilled-out gun you suggest would likely burst first (and I think tht's a good bet) would have to be submitted for reproof--where it might have failed without endangering the shooter.