Thats a nice lamp!
I havn't had time to build one out of elk yet, but have built a couple out of muledeer. I held mine together with long sheet rock screws. Drill a pilot hole just big enough to get the screw in. Don't screw it in all the way just deep enough to hold the antlers together, then back it out about three truns. Take a hack saw, file, dremmel tool etc, and score the screw, then turn it back in just past the score and snap it off. Then all you have to do is fill the little hole. This works great and will hold the antlers together very firmly. Good luck
Ivan