I just tried test-pepping my chest, and yeah, a bit too small. I based the measurement off my size for the FS Mk. VI chest. Problem is, the widest part of the MK. V is on the lower side straps. The mk. VI is at the upper chest plate. I'm upsizing it, should be done tonight.
Ok, this is 350mm wide. This should fit most people in the 5foot range, medium to small build. A bigger version's coming for the rest of you guys later.
http://www.4shared.com/file/252859343/83f4ffab/Reach_Torso_small.html