Marion,If you plan to make one of these from new materials from the fabric shops don't bother. Webbing and foam with velcro and buckles will cost a bomb. You can't buy the materials for the job for $40.00 American. From what I can see of the rig the buckles alone will cost $35.00.
Now used materials is a different deal. Try to get everything from a military surplus store. And good luck.
Don