Here's what I'd suggest: Get yourself some Resorcinol glue. It's kinda expensive at $30, but if you plan on making more of these laminated bows, it's more than worth it. I'd cut it down to 66" or 68" and stay with the 1.5" pyramid design. The hickory might be a little thick, but the beauty of using hickory for the backing is that you can thin it after gluing it on if you see your osage getting too thin during the tillering process. For a simple design, first glue and clamp on an 8" handle block using acetone to de-grease the osage and course sandpaper to rough up both surfaces.
After that's hardened, spread glue on both the osage and hickory slats and clamp it together (my favorite way is wrapping the bow in old bike innertubes cut into strips). A simple reflex will be the easiest to make and to tiller. Just put the tips up on 4" blocks and clamp the middle down so it touches the workbench. It'll look like this, but without the two mid-limb clamps. The reflex-deflex profile is a pain to tiller!
Good luck and keep us posted!