Remember a 14 3/4ga is smaller than a 14 not larger as is a 14/1. A 14ga = .693" while the 15ga is .677". The 14 3/4 would go .681" with the 15/1 at .685". I believe the proof house would have simply stamped the bore of a 14 3/4ga as a 15.
Only good thing I could think to say about one is at least one would not be tempted to shoot SAAMI spec shells from Wal-Mart through it.
8-Bore, your 11 5/8 should measure .737" dia. That does sort of have a nice ring to it, though a .747" should really get things Airborn @ a 11.16ga.
I suspect RMC could make brass hulls for any of these, at only one small extra cost.
