My First US Rifle

I recently traded for an M1 carbine and it looks like a typical "mix master." It has a Winchester reciever with serial number 1113186. The barrel is an Underwood dated 7-44. The rest of the parts are from many different manufacturers. Someone told me that some winchester/underwood guns were that way from the factory but that sounded kind of strange to me. Does anyone know anything about this or if there is any truth to that? Also is there a way to date the reciever by the serial number?

Thanks
Matt

Approximate date from one source is May of 1943. That means the barrel has been replaced. If you had pictures it would help.

what all would you like pictures of?