As funny as this sounds, I have heard that what they wore had a bearing. During the late 1800's and early 1900's it was common for men to wear starched collars and ties, even when afield, particularly the more "gentrified" the gentleman. With such a stiff, high collar comfort demanded a head up position.
I have heard this story a few times. I have never believed it. The have also read that the upright head, away from the stock, was historically to protect from flint locks and early percussion caps and the "flash in the pan" and that makes some sense. Traditions die hard and the dimensions from that era could have carried over.
As well, Americans have usually shot walked up game. Rising targets with the gun coming up to the shoulder as the eyes watched the target. I think the early American upland and wildfowler shot these guns with their faces off the stocks or just touching them. And, with the sharp drop to the heal at 3" the guns would have kicked up sharply. Face off the stock might be a defense mechanism. (If so, it is sort of funny that the cause of the problem created the method of shooting.) They would shoulder the gun and look down the rib without the face stuck to the stock.
My understanding is that the English game guns, with the much highter combs, were because those guns were used on driven game coming in from in front and high. The shooter was able to shoulder the gun well in anticipation of the shot.
Anyway, my .02 which may be about what it is worth.
Jake
