I have several .223/5.56 cal magazine repair kits for sale, all of the parts are there and "can be" resembled. All, but one of the repair kits are factory stamped with Colt logo on the floor plate. The single kit without the Colt stamp is an extendable setup, which can hold 30 or 40 rnds.
Colt AR15/M16 GI Mag Kits
(5) 20 rnd - $20 each (4 straight like in photos and 1 curved style, all of them are GI metal)
(2) 30 rnd - $25 each (1 plastic extendable 30 to 40 rnd and one GI metal)
(1) 40 rnd - $25 each (GI Metal)
The price of the magazines includes shipping