Mark, shown below is a 1908 hammer gun that had 25 3/16" barrels when I got it. I knew I would find another barrel to go on it, well as of now this gun has 4 other barrels that go with it. The latest is a 32" Nitro Steel barrel from a 1928 Specialty Grade, vent rib, with screw-in chokes. I bought them and they fit right on that hammer gun plus they fit right on another Specialty Grade c.1937. So you can never tell unless you try it.
The reason I believe most barrels fit other Hunter Arms guns is that they had to be made so that the tolerances were close to other guns so that the man hours spent were cost saving. Even though all started out as production guns, they were all hand fit and then some moved on to become the higher grades where more hand work went into them.

The beavertail for-end was fit to all the other barrels also, that takes time because once the for-end iron is fit to one set of barrels you can no longer do anything to that for-end iron, it all has to be on the other barrels loop. Plus this beavertail has the roller release and so all the other barrels loop need to fit also on the back side.