You seem to be correct about the Ducks. Even a prewar 3" gun leaning up behind the barn, not marked Duck or Magnum, has an 11" forearm. However, there are a bunch of short barrel skeet guns that also have the 11" forearm. Yes, they came from the factory that way and they look like heck. I just measured a 1935 12 gauge Tournament with one of those things hanging off the front and now I know why that gun has always looked like it had 24" barrels when they were actually 26". Schwing gives dimensions for the Hession forearm but the difference between this and the field forearm is very slight, so it may be hard to recognize without careful measuring with calipers. There is more difference in forearms of the same style in different eras and days of the week than there is in different styles. If you want your slim field gun to have a Hession forearm, all you have to do is say it.
