Was going to do the 602 clone but decided to restore my 82 SP1 to its original condition and build a very early 604. Here are the pics. Barrel is a cmpb that I had the FSB modded to look earlier by JT. All other parts are original except the very early SP1 upper and dimple sight screw which is a reproduction. Also of the receiver is a NDS partial fence. Carbon steel gas tube, transitional bolt catch,dimple mag catch with many circles mag release button, c stock, 602 grip, edgewater, 601 FCG, no drain screw, 601 pistol grip screw, 601 receiver extension with hole, early armalite port door, 1 no drain hole hand guard and one polished to look old, original dimple pins, original 3 prong refinished by JT, p marked bolt, flat head firing pin, milled FPRP and early chrome carrier with 3/4 gas key with square stakes. One day I may find an earlier barrel.