The main thing that I don't see are some water-purification tablets.
Also, if you already carry a FAK on the belt, do you need more bandages and FA-cream in your PSK? If you would remove them, you could fit some HD aluminium foil in there.
Another thing you could fit in there is a magnifying-glass.
I assume you carry some form of shelter on your person?
Nice PSK!!
Jim, I'm glad you brought up a magnifying glass. Do you know where I can get a fresnel lens? I've tried all the major stores in town without success. As for shelter, I've been looking, but can only find 55 and 42 gal bags in black. I'll break down and get them, I suppose. Usually though there's at least 1 30gal in my camelback, as well as a space blanket.