Here's another example of a project piece- a primitive alice pack
Extremely valuable because you can haul firewood, a carcass, a large woven basket, or a leather bag.
Typically you would carry your tools and shelter in, detach them from your frame then take the empty frame to haul things to your camp.
The frame allows you to carry things that are both awkward (a carcass), massive (a heap of straw) heavy (a car battery) or sharp (firewood)
You need a piece of wood that you can gradually bend into a "U" and which will retain it's shape.
Tree root is entirely acceptable though getting it to hold it's shape can be tricky.
To this would will fix your two "L" brackets facing forwards, the arms of this is what you will attach your belt strap to to hold the pack securely.
If you're making this for someone else you would leave these unattatched until you measured the wearers hip/shoulder length.
The best way of securing this by far is to make a hollow in the L to match the U piece, then use a sap/ash glue, then bind that joint in fibrous cord soaked in the same glue.
You would then weave a mat across the "U" to make a fairly comfortable pad for your back. Cord would be ideal- but flexible vine would be sufficient.
This effectively tensions the "U" and thus makes the whole thing very sympathetic to actually wear.
You would add strapping, one belt strap between the protruding arms of the "L", and two wide straps from the to of the frame to the bottom- don't attach these to the protruding arms of the L because these will be too wide, attatch the strap the the bottom of the U and a simple noose knot is fine because in an emergencly you can detatch the pack by pushing the nooses right off the bottom of the frame, this is not going to happen by accident because of the weight of the pack.
By doing this you also get two neat straps with which to suspend the pack if you are using it as a work station; or to pull it up a tree/cliff.
This is the design for the survivor, and it can be made in 20 minutes provided you have the materials.
If SHTF you can use salvaged materials.
The frame can be made with sections of fencing wire, plastic pipe, a bent piece of scrap metal.
the L shaped protrusions can be made by spearing two plastic bottles onto the bottom of the frame or worst come to worst omitted.
The mat can be made with twisted cloth rags, electric cable, rope, or the bottom of the U simply tensioned.
You could actually make this entirely out of a single dumped couch /mattress, from a wrecked tent, a car seat, a bicycle. or in fact entirely from fencing wire.
If you made these from hemp rope, bend branches and natural glue you could probably sell them for a considerable amount at local markets.
You might have to demonstrate the general utility of the alice style pack in the carrying of something like a folded scooter or a pile of wood.
Or you might have to buy some cheap canvas bags/sacks to sell with them so they were ready for general use.