IBM Carbine - What have I got?

IBM SN 385389X, IBM Barrel (undated, stamped IBM Corp.), P proof further toward receiver. Stock with NBP over FJA cartouche on R side of stock and very faint crossed cannon about 2.5 incches forward and a little below. Sling channel marked TN (with some other letter that I cannot fully make out. No markings on recoil plate. JAU (5 or 6) and 0060 on adjustable rear sight. Lever safety. Mag release button is marked sideways M (legs facing muzzle) with an upside down WA above that. JM marked on side of forward (bayonet type band) and CM on undeside of bayo. lug. Heat lot (?) on left side of trigger group marked N and 9. Op rod marked M, Hammer marked M. Front sight has M in channel rear of blade. Round bolt (no markings that I can see - except that it is electro-penciled on undersife with an X152940.

Can anyone help and identify if it is original (or correct parts?) I am puzzled by undated barrel.

Thanks.

Typical rebuild is what it sounds like. Barrel and receiver are a good match. Trigger housing is a National Postal Meter. Parts in the TH are again typical rebuild parts. The undated barrel is correct.

Lets see how it shoots. No muzzle gauge, but M2 ball round from Ogive back stays exposed - about 5/16th, nice bright bore. Thanks

Typo in my original posting...stock is cartouched NPM over FJA. Does that make it a Postal Meter stock? - or is it right for an IBM?

Thanks

:thup:Yep.