Looks very close to the issue colts I used back in the day (late 70's-early 80's). Also, guys used to coat it with "Kal Guard" spray coating, which was a dead ringer for the early colt stuff. Contact "KG Gunkote" (the current company) and ask for their early legacy coatings. I used it to build a couple of "personally owned firearms" myself. It was a nice charcoal grey color, that coated all your different gun show parts and made it look like a factory colt, which is sorta the same thing you guys are doing. If I'm not mistaken I think they still make some "original formula" stuff. Just make sure and ask them for the stuff they made for the "Teams".
Gotta laugh, used to keep my "CAR-15" in a spare bbl bag like that too.