Well, I picked up a nice-looking , round-bolt, 4.5M Rock-ola carbine yesterday at a very good price. Its got a type II barrel band on a nice low wood stock with IO in the slingwell. I don't see any cartouches, but the stock is in what appears to be unmolested condition with very minor dings. I figure that the stock might be Inland? The type 2 barrel band is not a cut down, and it is marked J.M.O. I don't know what that means. Also the front sight is marked J-Q, and the front sight appears to be added later because its finish is a brighter blue and the blue on the Rock-ola barrel. The rear sight is a type 3 sight with a shield and a letter in it on the right side, Since I am kind of new to M1 carbines, I have not yet dissassembled the carbine yet to look for marking on the other parts, but i will. meanwhile i'd appreciate input on the stock, barrel band and both sights.

Oh yes, the carbine has a vintage sling and oiler on it and a tarnished M2 -marked 30-round magazine. The store that sold it said they just took the carbine in, as is, in a trade for an AR.
Thanks for any input on the codes etc above.