Thanks for the feedback friends.
Arvin, I am wondering how much wiggle room I'd have with a wood shaft. I probably need to start making my own. Poplar would be very easy to get.
Did some work tonight. Got the form for the smaller flight bow cut out. Made a few adjustments to the line to simplify it a bit. Got the billets cut down to a more reasonable size. They're a bit wedge shaped and not super wide so I need to be careful to get as much width as possible. Shaved down a piece to do a density check at some point. It's definitely hard, aged osage but not necessarily the most dense stuff I've used. I think I'll be able to get 1.75" wide. I have a lot of wiggle room for the length but I was hoping to keep it short, close to 54-56" for primitive flight.