I built this 870 way back in 02/03.
Pre production Magpul M93A (named MSS at the time) on an ACE A2 grip/stock adapter (I trimmed the lock as I like to run this at 12"LOP or so),
20" barrel with Vang style elongated forcing cone built by Jon Tank,
Custom top rail (there were no ready made kits at the time),
Aimpoint M2 in an ARMS 22M68 mount,
SGT tritium rear, XS tritium Big Dot front,
Surefire M69 picatinny forend, M900A light, with an unbelievable 900lumen Lumens Factory Led head conversion (and my 500lumen X300 Ultra riding in the lefty-tumbbreak position when not in use on a handgun),
Mesa Tactical Shell holders, 6 left, 4 right,
Jon Tank +3 mag tube extension.