from the Wikipedia article "10 different manufacturers made the M1 Carbine including, Inland (General Motors), Winchester, Underwood (of typewriter fame), Rock-Ola (Jukebox Company), Quality Hardware, Grand Rapids (Irwin Penderson & Saginaw SG also a GM company), Saginaw Gear (another GM company), National Postal Meter (supplier of machines for the US Postal Service), Standard Products, and IBM."
So the mark should resolve to one of those. As WWII carbines typically didn't have the adjustable rear sight and bayonet lug (late war additions but widely adopted in post-war retrofits) your gun was probably redone after the war. So any blend of parts is possible.
I used to love being able to hit hard at 1000 yards. As I get older I find hitting a mini ram at 200 yards with the 22 oddly more satisfying.