Jerry,
There are a couple of books on finger weaving, but none that I've seen of the type Tom did with the hemp on that tumpline strap. Even with the strap in my hand and some magnification I can't figure out how he did some of it. A good book that will show you the basis of finger weaving straps and sashes is by Alta Turner called Finger Weaving: Indian Braiding. You can find it at bookfinder.com or abebooks.com for about $6.50 including shipping. It's a small, well illustrated book that will show all the basic techniques. Another book that shows basics of finger weaving along with basic quill work techniques, how to weave cedar or basswood bark bags or how to build a birch bark canoe is by Carrie Lyford called Ojibwa Crafts. It was originally published by the bureau of indian affairs in 1943. You can get a trade reprint of it through bookfinder for about 8.50 including shipping or an original copy for about 10.50. I have the original version, fascinating reading.
Tom