Finally got the venerable Winchester Model 12 and Ithaca 37 Featherlight in my collection. M12 is 1955, full choke, 30 inch barrel. M37 is 1948, full choke, 30 inch barrel, aftermarket recoil pad.
I'm amazed by the build quality on these shotguns. The M37 is the smoothest, and ejects shells several feet. It also is the lightest at 6-7 lbs and balances the nicest. For upland she will be good. The M12 is solid, heavier, and is quality. About 7-8 lbs, the balance is good, but not as good as the Ithaca. The stocks are thicker than the sleek Ithaca. Compared to my Mossberg, they are about the same weight, but balance much better. Even with the Aluminum receiver on the Mossberg, the steel barrel up front makes it muzzle heavy. The balance point is not at the receiver. Also, I think Mossberg's barrel is thicker and has the ventrib. It is also a more compact design as you will see in the pictures.
I'm also intrigued that the Mossberg takes some of the best qualities from both of these shotguns. For example, the dual extractors, shell elevator staying up like the M37, bolt release similar to Win 12, Barrel attachment system, Mossberg's receiver holes are exactly in the same spot as the Ithaca. I'm sure there are more similarities. The bolts, bolt slides are also similar to the Ithaca.
Pictures from top to bottom (1948, 1955, 2008):