I fond Mollies the easiest to pull off, for some reason, and the rest tougher. I can't explain it, but I do.
Steve, can yopu possibly chase a ring on anu of the elm flooring? If so, do you have enough thickness for a bow? Or, can you glue up enough thickness? Elm, all elm, is good stuff if designed around.
Can you back an elm stave with the rawhide? Or the maple? The maple might make a self-board bow, if the grain is ok.
Bamboo flooring is fine stuff, but it takes a lot of set. It just seems to. I had the best luck with that stuff glueing up in a trilam, where I added reflex to backing and middle, then glued it into about the same reflex again when I added the belly. The backing/core/belly should be 25/25/50, or 30/30/40 thickness ratios. This kind of gets fancy, but I made some great R/D bows out of bamboo flooring.