Serial number places it as a Colt 6721, should have been made in about 1996. We have a 6721 data base here:
ar15.com/forums/topic.html?b=3&f=118&t=271173I would guess it left the factory like this:
LBD 001949 gray finish, CAF upper forge code, carry handle forge code?, old style buttstock, modern M4 /nut/buffer/four position receiver extention, mag fenced lower, small pivot pin hole, weep hole not drilled, large trigger pins, SPORTER half round bolt carrier, blue extractor buffer, roll marked COLT'S MFG CO. INC, no pinned in sear block, LEO roll markings on right side, blue lable box, 16" barrel, peel washer for flash suppersor, no "T" numbers on top of receiver, barrel marked C MP 5.56 NATO 1/9 HBAR
IF that short barrel is factory original it would be marked something like this under the handguards:
C MP CB 5.56 NATO 1/7