I built a similar rig off of a
Head On Tactical 4 Mag AK/M4 Chest Rig - Compact Type. After I got out of the military, I didn't find it necessary to have a full size RRV that carried 6 mags plus whatever else I needed for a full combat load. So i sold it and set out to put something a little more compact and practical together.
Took me awhile to find it, seems to be a small company but the main reason I chose this one was the already built in mag pouches to reduce too much bulk from adding too many layers of PALs. The rig itself is also one large map pouch.
I removed 3 of the bungee mag retainers and added kydex inserts. I left one to allow the option of carrying a pistol on the rig, though now that I have a paddle holster I don't know that I ever actually will again. I upgraded to an SOE padded H harness but probably wouldn't spring for it again. Great piece of kit but I'm not wearing this daily for patrols and if I were it could be mounted to my plate carrier. I usually leave the X harness that it came with on it because its much more compact and fits in to a pack much better.
My only complaint is that my IFAK is a little bulky but even though I don't plan on being in a combat zone anytime soon, I can't bring myself to downsize its contents.
(I can't for the life of me share an image on this forum anymore. No matter the hosting site, it appears in the preview but when posted just turns to a link.)