That left limb looks severely hinged in that last braced picture. I'm guessing that crack is in the left limb near the hinge, right?
I don't think you'll be able to save it really. But you can always try! Just don't try to repair it with Gorilla wood glue... Since it's sinew backed, why not use some more hide glue? Makes the most sense.
I can't remember anyone successfully removing sinew from a bow by soaking it. You can try, but I think this bow is not salvageable, nor is the sinew.