Forgot to post, I got my Maxpedition Universal Holster and it works great with my Versipak Fat Boy. However, it is a no go with the 5.11 Vest.

The Vest has a couple of narrow strips of velcro on each side. Weird. I searched my stuff for the kit that came with the 5.11 holster and double mag pouch. I found a very thin (flimsy) square panel of material. Ok, that work to attach to the strips in the Vest. I tried to attach my new holster to it, no go -- the weight of any of my pistols causes the square to severely slouch. Not secure at all. In my "kit" I found another square of material that is very stiff, that attaches to the other square, but unfortunately is the wrong velcro side for my new holster to attach.

If I can find a square panel of velcro (don't know what else to call it) that has each type on each side, it might work but seems like more fuss than it is worth.

The holster however does work great in the Versipak to secure small pistols. In fact, my Glock 27 and S&W M&P 9c fits great no resizing or moving required.