French Colonial: The dog chew toys, years ago they were real rawhide but I'm not sure if they still are. They are also very thin. Crazy Crow sells tom-tom drum covers made of rawhide. I think about $20. They have white paint on one side.
The material is large enough to cut in half and make two rawhide sheaths. It is the only thick rawhide I've found. The white paint can be scraped off in a few minutes so not a big problem. I made one sheath with this material using lead rivets. Worked out well. however I think brass tacks would be better. Crazy crow also sells real sinew. Let's talk about that.....
You strip off several sections of sinew. You can keep splitting it into as fine a thread as you want. When you sew it, soak it so it is pliable but leave one end dry so it is stiff enough the thread through a hole made with an awl. You use a whip stitch, so piece #1, only 10" long. You pull through until only 1" is left- lay that along the edge. Then whip stitch so that 4 wraps cover and lock the tag end. When you get down to the last inch, lay that along the edge. Use a new piece- pulling through until only 1" is left and lay that along the edge next to the 1" from piece #1. The next 4 wraps cover BOTH the tag ends along the edge. You can proceed very quickly. The reason I am telling this is because folks think real sinew is difficult to work with-not true. It is easier than fake sinew, period correct, and much stronger.