Um, yeah, no, there is most definitely not 3/4" inches of wood left in the handle of this bow.
What practical difference does it make? Even if there is no wooden handle under the bone plates, there must be something in there. What difference does it make whether it is one piece (with the limbs) or scarfed pieces?
The handle is rather thick. Though just 1 inch wide (in the front profile), it appears to be a couple of inches thick (in the side profile) at least. That means it is more likely to have a separate handle piece and the limbs are spliced into it and the bone plates are added. Do you have any idea how wide (high in the side profile) are the bone handles? Practically it would be a lot easier if there is wood under the bone plates. What difference would it make if it is the same piece as the limbs or a separate piece? Either way there must be a separate piece on top of the limbs (in side profile) anyway. What difference does it make whether it is made of the same bone plates or another separate piece (of wood or whatever) under the bone plates? There are many ways to skin the cat.