I do something similar, although it's not really a "survival" kit. I have a large wallet that has a pocket in the middle for a pen. There are two pockets that are roughly 3x5". I got the idea to put in a OMNISEAL bag from reading another thread here. Inside the bag, I have:

* 6 small bandages
* 2 round wooden toothpicks for htose annoying times when I get some steak or chicken stuck between teeth
* 5 matches in heat-shrinkable tubing (I've been looking for some small strike-anywheres... any ideas?)
* Spare truck key (most of the handle has been cut off to get it to fit widthwise) for when I lock myself out of my truck
* 1 safety pin

The big challenge is finding items that are thin enough to not make the wallet too thick. I think I've done a pretty good job. I also carry a Leatherman Juice Pro, an ARC-P flashlight, a USB thumb drive, and a cell phone. In the wallet there are 3x5 notecards for taking notes and the pen in the center pocket. Also the area for holding dollar bills is rather large, so I fit half of a folded-up paper towel in there.