Dealers that won't sell the whole full rifle to civilians is not BS, it's really the manufacturers policy.
I bought my 16" carbine separately at the Equipment Exchange board and the quality in fit and finish is as good or even better than my other Colt.
They're not perfect either and no high quality mfg are perfect, sometimes they make a few with defects, but the company have a well known good policy in fixing the problems.
The LMT has Mil-Spec features like real M4 feedramps, correct F type FSB (not marked), MP tested barrel and bolt, Mil-Spec size buffer tube which are compatible with Vltor, Colt, Sopmod and Stag Arms stocks.
The LMT buffer tube has a light grey color finish but there are three drain holes at the last three rear stock detent holes.
The only feature that's not that great is the high shelf of the lower receiver, but other brands have them too like CMT, RRA and others.
Another good value brand with Mil-Spec features is the Stag Arms with the special edition M4 1/7 14.5" with perm Phantom FS upper half, if you don't care about 1/7 twist they also have the regular 1/9 twist uppers.
You can't go wrong with Bushy, Armalite, etc., for less money but you won't get some of the Mil-Spec features that I mentioned.