BCM Vertical Grip Mod 3 1913 and KeyMod is now available.
Link:
http://www.bravocompanyusa.com/BCMGUNFIGHTER-Vertical-Grips-s/171.htm
Price: $17.95
KAG is a hand stop and there is 1913 Picatiny rail version as well as Key Mod version.
From: Bravo Company USA