Deer bone, yes it will work I've used a lot of it, the hip bones make the best handles for me, they offer the widest slabs.
I've used turtle shell like what you show too, it works but there are some pitfalls. They include, getting it flat enough but still thick enough, then you have the option of leaving the scutes on or taking them off. leaving them on is a pain, if the turtle has been dead a while the color from the scutes will sometimes bleed into the bone of the bottom plastron (bottom flattest part of the shell) giving it some unique off white to almost yellowish red coloration. I have some guitar picks I made somewhere that exhibit this.
Boiling bone doesn't help much to flatten it like horn or antler. It can be done but with a lower success rate and not as dramatic of results as you can get with horn.
I've used just about everything for knife handles. I started when I was very young and scrounged all the materials I could. I've used deer bone, bear bone, elk bone, cow bone, dinosaur bone, giraffe bone, turtle shell, turtle shell bone, mussel shell, cow horn, buffalo horn (foreign and domestic), rams horn, whitetail antler, muley antler, elk antler, reindeer antler, caribou antler, red stag antler, sambar stag antler, abalone, mother of pearl, acrylics, micartas, jeancartas, carbon fiber, brass, coyote jaws, deer jaws, too many woods to list, snake skin, dinosaur egg, mammoth ivory elephant ivory, warthog ivory, hippo ivory, mammoth tooth, coral, fossilized coral, tree bark, and a bunch of others I can't remember right now. I have even tried laminating scales off big grass carp to form handle slabs. It looked very unique but the grease in the scales kept the glue from holding well. I have a new plan to fix that so I'm gonna try it again this year if I can remember. I even have some gar skin I want to try but haven't had the opportunity to put it on a knife yet. You can use just about anything as a knife handle if you work at it long enough and try it enough ways.
Hell, Oupa even made handles out of kangaroo dung and cow pies!
If sh!t can make a handle anything can!!!!