The upper is factory Colt, produced 2013. The date on the barrel is correct, as it reads. You will also notice the steel plate fixture in the receiver (which showed up in the last few years).
The lower is factory Colt, produced early 2000s.
The upper and lower began lives on separate rifles, manufactured 10+ years apart from each other, and assembled together by the previous owner.
The muzzle device was pinned to make the rifle legal (16").
Awesome rifle.
There may still be remnants of a yellow dot under the FSB? The FSB will be F marked. Basically the upper is not technically a 6944, as it would not have been manufactured for your semi-auto civilian/leo rifles. The upper began its life on a military contract R09xx series rifle (i.e….. with "happy switch."). With military contracts, custom configurations can be ordered, as described on Colt's web site:
http://www.colt.com/Catalog/Military/Products/Advanced-Colt-Carbine-Monolithic-ACC-M#100238-features--models
I understand that a decent volume of Colt goodies was sold/liquidated within the last couple years to absolve some of their debts. As a result, a very small number of these uppers ended up in civilian hands. I lucked into a couple myself (I sold one to to veeklog). They exhibited some handling wear, but low count was obviously very low, possibly test fired only. They are awesome, accurate, and handy uppers, especially if you are a guy who prefers a fixed FSB.
Nice score. The lower is desirable, and sells for around $700-$900 on its own.. The upper, who knows? It is undoubtably a rare bird, in a kick-ass configuration. I'm sure someone with a happy switch and/or suppressor, would salivate at getting their hands on one. Throw in your hardcore Colt collectors, and who knows? In fact, I just listed one on Gunbroker.