See if you can find an old antique feed sack. Cut it into strips 4" wide until you have enough length to fit around your body. Sew them together and then sew the two edges of the strip together. You now have a tube. Straighten a coat hanger and run it thru the tube. Then use it to pull the end thru the tube. Pound the stitching to flatten it out and center the seam. Hit it with a steam iron to set everything. Sew it to your pouch.
This is tanned deerskin, but a cloth one will serve your purpose.