The Woodsrunner Line ft. Haversacks and Snapsacks....Product Announcement with Paxton Creek Supply. 

Those tubes were originally an old pant leg cut off, repurposed. I made a Hobo Roll that would be a good product for you to make & market, nothing like it on the market. I made mine out of a piece of poly tarp for waterproofing contents. It is designed similar to your haversack as there are pockets on both ends but is rolled up. I cut a rectangle piece of tarp about 26" x 90", then folded up both ends into pockets using 2 sided carpet tape making it 26" x 50", then turned in inside out so tape side is inside and now it is 24" x 50" with large pockets at both ends. Stuck in a torso pad, inflatable pillow, bivy bag, gloves, down blanket, etc in the pockets, roll it up with a jacket inside, use cinch cords to secure the Hobo Roll then hook a strap to the cinch cords. When I roll it out it becomes a torso sized ground sheet/pad ready to sleep on. Will be hiking with it on Appalachian Trail late March.

Now we understand Elon M when he was talking about his problems with Tesla - manufacturing hell