Your Thoughs on a retro "rebuild"

[rondog]

I recently bought an IBM carbine, s/n is 3706483, and it has an Underwood barrel dated 10/43. This rifle was purchased from the CMP by the guy I bought it from.

Can anybody tell me, by the s/n, the approx. date this rifle was made? And would the Underwood barrel be correct or a replacement? I don't know if IBM made their own barrels.

Thank you! This is my first M1 carbine, and I'm totally clueless about them. I don't have any reference books or anything yet, so I'd really appreciate knowing the manufacture date, if possible. About the only thing I DO know about it is that it's a real blast to shoot this little thing!!!