I'm with Jerry and Jim on this one. Most vintage American doubles, Ithacas being about the only exception, didn't even come with the chokes marked. And if they were full with the old fiber/cork wads, then they're REALLY full with modern plastic wads. Why not open them? And Americans have grown taller in the last century or so, which means that LOP on a vintage gun is often too short for today's shooters. Besides which, most of those vintage guns offered pads as an option--or at least that's what my 1940 Shooter's Bible tells me. So, especially if you use a "period" pad--with which the gun might have been ordered anyhow--why not?
If the gun's truly collectible and high grade, then you're well advised not to mess with it. But it's not much good to you if you're going to hunt with it, or shoot targets, and it doesn't fit or has chokes that are all wrong for the intended purpose.
