Iosat? Uhmm... OK.
I would add a length of hacksaw blade to your kit. It weighs nothing, takes up almost no space, and is a better striker for the flint that a stainless steel knife blade is. It also protects your knife blade. And a hacksaw can be awfully nice at the oddest times. Wrap it in electricans tape to keep it from wearing holes in your pack, and to make a handle with later. Alternatively, you can get reciprocating saw blades for metal/pvc which work pretty good, and ones for wood. You'd want to improvise a handle, but one of each wrapped in electicians tape would take up almost no room.
Something a little faster than flint and steel. I can use them, but I've been too cold to get my hands to work that well. As an ex-smoker, my hands will never forget how to use a lighter or matches, no matter how cold I am. This is also a really good place to have redundancy in general.
If you can, upgrade the walmart nalgene knock offs with nalgenes. The nalgenes are heavier, and cost more, but I kinda killed one of the wallyworld specials by sitting on it. Also, fill them with boiling water, cap them, and let them cool- that will give you two liters of water, rather than 8.4 ounces. That's a juice glass and a good sneeze worth of water.
The nalgene cups are usually on eBay, new, for like 3-5 dollars plus about the same for shipping. LL Bean has them for a little more IIRC.
Add some 4x4" gauze pads. Useful.
A flashlight that uses the same batteries as the radio. Even if you EDC one, this a good thing to have a spare of, and not just a little microlight. Have you changed the battery in that before? Do you need a tiny screw driver? Do you have said screw driver? Could you do it in the dark?
Swap the snowflauge bandana for a red one. That can be seen a lot better than a strip of flagging tape.
More duct tape.
This is an oddy that I've started to play with- 5 feet of 1" wide webbing, and a double adjust side release buckle. Awfully nifty, you can make a lot of things out of it. It rolls up about 2" across, and inch high (obviously), and the buckle is about 2.5" long. It might be a little big for this bag, but as I inspect my kits, those that can fit it will get one of these rolls, the buckle and maybe an annex clip or two.
As others said, bug repellent. I know people love deet, but the only thing I've found that works worth beans on black flies is something called Green Ban 2000. It's from Australia. I've not seen it online, but that's becuase I've never looked, I get it locally. It also has the advantages of being kid/pet safe and it won't eat your nylon gear. I don't know if they have it thier web site, but the guys I buy it from have a webstore at vtarmynavy.com. And you smell good, not like a chem lab oops.
On your oven bag, have you marked the levels for one, two and three quarts? Useful to have.
Long bit on iodine tablets.... (can't tell I've been messing with them or anything)
PotableAqua goes flat in about six months if you repackage it. Once the seal on the factory body is broken, that clock is running. In the factory bottle, good for a year. Others have mentioned what iodine will eat through- everything but teflon and glass and some really spiffy plastics. The guys you put in the ziplocks are probably dead already. Check EVERYTHING that they were in with, they might have eaten something else along the way.
When you repackage them, you need to find PTFE septas. They are 1mm thick little disks that go in the caps. Don't try to make your own with teflon sheeting, trust me, it doesn't work very well. And put a turn of teflon tape around the neck of the bottle, it's worth it. For all the trouble, if you can find and stomach the clorine pills, either PA or MicroPur, it's easier to just use those, but as big as this bag is, why bother? Just toss in a full size bottle.
If you do repack iodine, like I do for my PSK, check it weekly, and wrap something just below the cap that will stain easy. That way you can tell if you've got a problem before it does something like dissolve your flint.
Sorry for the rambling. Didn't realise this was quite that long.
_________________________
-IronRaven
When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.