When I braintan deerskins I usually wind up with some stiff spots around the edges and holes, and little strips that are just too much trouble to try to soften. I cut them off before making anything out of the buckskin, and wound up with a pretty good amount of this sorta-rawhide-sorta-buckskin stuff.
Then, when I tried my hand at making my first knife from an old file and deer horn, I threw these pieces into a pot with some water and just kept boiling it down until it was a sticky, nasty mess. I stuffed the hole I drilled in the end of the horn with it, sank the half-tang in, and let it set for a while. It worked better than I would've thought. It lasted for years, in fact, and only loosened up when I got it thoroughly soaked in saltwater during a sailing trip. (Took it underwater with me to cut some line. Stupid.) Never a problem with freshwater on canoe / kayak trips. Go figure.
So, I dunno if that's anywhere near PC, but it's sure hide glue, and it certainly worked for me. Seems like the kind of thing a hunter or trapper might do, too.
