Try Googling Johnny cakes or Pemmican. You might also try Primitive Skills, Pioneering skills.

An Outdoors Skills instructor from wayyyy back name of Larry Dean Olsen out of Utah probably has something in one of his books. Fashioning knives, spears and fish hooks from flint and bone.

There is a cracker of sorts called 'Pilot Bread'. It is about 1/2" thick x 4" round. Ninety eight percent of finished product is destined for Alaska as it is a staple up there. It comes in a large blue box about 5 1/2-6" square x 16-18" long. It is manufactured by just one facility in the lower 48. I have seen Pilot Bread in the bulk foods department at Winco Foods in western WA state. The bulk pricing is MUCH more REASONABLE than the box price unless you don't mind paying $16 for a cool blue box full of huge crackers.
Stripped MREs like the fruit/gorilla cookies/crackers and jam-cheese-peanut butter, Gorp, kippered snacks, processed cheese or jam, quart sized kool-aid/ gatorade/ Tang this sort of thing are products I have used to good effect. MRE bread (if you can find it) could be made into a quick sandwich with what have you.

In days of yore when I'd been out for 8 days w/o resupply and we stopped to eat I was mighty glad to have anything to eat. Three of us were down to kippered snacks on Rye Krisp crackers w/peanut butter washed down w/Wylers drink mix and 1 orange to share amongst us. It was a feast.

By just using your common sense you don't have to spend an arm and a leg to score patrol rations. Check your kitchen first. Those small portion snap top cans of /skettii/mac 'n beef/mac 'n cheese etc at regular (big) grocery stores are by and large a WAY BETTER DEAL than same item at ANY convenience store. Watch the ads for sales and get these items at reduced prices and start a nestegg of 'patrol rations' ONLY to draw from when preparing to move out.
That's the way I roll.