Well, it is very unlikely that you have an original carbine, since that number* is 5,000 above the generally accepted cut-off for the first production block of carbines, and the second block doesn't start for another 25,000. The receiver sight, unless it is one of the ones fitted into the cutoff hole and not requiring a new tapped hole, will further hurt the collector value. The missing parts should be readily available. Value would be pretty minimal to an outsider - you would do best to simply treasure it as a family heirloom.

*a more definitive search could be made with the whole number. If you have had it in the family for 60+ years, it isn't stolen - so there is no reason to be coy.