I'll have to object to backing the bow. Osage doesn't need it, and a backing is just one more thing to go wrong.
Making a Meare Heath style bow out of super-dense Osage will give you tons of limb mass. Osage is better suited for narrow bows, imho. 1.25"-1.5", with a gradual width taper. You want Osage to really shine, then make it that way.
The take down sleeve idea is good.
If I wanted a short hunting bow, I'd make the bow bend through the handle, with a length of around 60-62".