I drilled 4 holes in both pieces. Then I anchored screws with JB Weld to the backplate so they stick up. I cut the screws down to a size that left about 4 threads showing with the collar in place. Then I dremeled out the shoulder keys and JB Welded in some nuts. This way, the collar piece actually bolts on via the shoulder keys. I also have a great way to attach my cape. http://www.thedentedhelmet.com/showpost.php?p=126660&postcount=72 I also have velcro on my vest and armor to keep the clloar from sliding around.