How narrow are those limbs Knapper and how long had the stave been seasoning? It looks ELB-ish in design, which (if I'm seeing it right) I would not recommend for a shorty. But even so, I wouldn't expect osage to take set at 14" unless your wood was green or your target draw weight is so high it's exceeding what the wood can do. I've not had any luck with a backing pulling set out of an osage bow. You need to work through why you're getting set so early. I'd like to see the bow unbraced and from the front to get a better feel for it. Very odd that you'd get set so early unless the wood is green.
George