It is pretty easy to make a DIY sheath. You can use an old weightbelt. Fold it over on itself for a few layers until it covers the knife and also has a loop for the waist strap. Now when you got the configuration figured, tape it with duct tape. Then crush it hard at each fold with a vice. Now it is in the shape you want. remove tape. Next, use a hot poker to burn holes through several locations close to the edge. Use aircraft safety wire through the holes, twist and tie up the sheath. this serves the safe function as sewing. Then for the finsihing touch, cover the lower section with gray duct tape..
Interesting...this is simular to what I was orignally thinking of. When I get back to the States in a few months, I will give this a go.
Thanks,
~ME~