Which Colt AR15 lowers have mil-spec takedown pins and mil-spec tirgger control group pins?
Edited to clarify title.

I am not aware of any---except for the mythical "white label" lower that Colt shipped in the late 80's and early 90's. I have never seen one, but have heard that they all were stamped "AR15 A2 HBAR"

Will uppers made by other manufactures fit onto my Colt (pre-ban for 6 more days) Lower?  The front takedown pin has the screw in one side, but the diameter appears the same as the rear pin.

Yes, just use the same screw.   There is a chance that some upper you may buy was drilled larger for a Colt large-hole lower, but that's probably less than 1%.  

My Colt Sporter Target pre-ban had (Note HAD) the screw type fake pivot pin. The raised fence was already drilled for the detent and spring, including the "weep" hole. I simply removed it and replaced it with a standard diameter GI pushpin, detent and spring.

I may be wrong, but I THINK Colt stopped using the large pivot hole when they went to the A-2 type lowers. Using a "fake" push pivot pin with the screw in the left side of it. Some of the fences are drilled for the detent and spring, and some aren't.

I'm no expert, just what I have observed from samples I've seen. However, as has been stated below, there are all kinds of variations in Colt's with consistency a real hobgoblin.



Lonny

EDIT: It DOES, however have the large FCG pins, unfortunately.