i have a M11 that is roll engraved with the legend "Sportsman" on the right side of the receiver. it only holds two in the magazine. offered by the factory about when the three shot limitation became law. it has the safety button in the ttrigger guard, if that means anything.
i bought it, used, in 1948, in pristine condition, after the M48 was offered. i liked the "humpless" 48, but my yardmowing income curtailed my buying of a new shotgun or any new gun.
it had a Nydor sight on it. this sight, i was told, was invented by the man that developed the Norton bombsite of WW11 fame. it was/is mostly a rangefinder, for duck hunting, and not primarily a sight. story was that the circle in the sight corresponded with a Mallard duck's wingtips at a distance of 40 yards, the socalled optimum range to kill said duck. i too, took the sight off after using it for a short period of time. i was disappointed when i could not hit a sitting squirrel, much less a passing dove. removing the rangefinder sight reverted the M11 to what it was, a dasmn fine shotgun. it and i have lived happily ever since. quite an upgrade from a single shot 20 guage. i have always loved it and have taken especially good care of it, therefore, it is in about the same condition as when i got it it is not for sale.
in the late 50s i came into another M11, an old warhorse that had the bbl cut down and an adjustable, Polychoke, on the end of it. it kinda worked as advertised. i swapped it off for a Colt Match Target ,22 pistol with 4" and 6" bbls. i wish to heck i had them both back, but, that was back when guns were tools and not collectibles. not so, now that i am much older.
if you run across a M11 at any reasonable price, consider picking it up.
and, be sure to pay attention to the friction ring for high and low brass loads.
these old guns work as well now as they did back when they were state of the art, and, that is very well.