For hinges (which were the long piano hinges, cut to length), I first just clamped them in place to make sure that when the hinge closes it the top and bottom shell mate together the way I wanted. I actually had to do some adjustments on the left gauntlet.
Once I was sure everything was ready, then I used a generous amount of JB weld on the flat part of the hinges and clamped them in place on one side, with the rod part of the hinge facing the outside of the gauntlet. I paid special attention to make sure the JB weld didn't leach into the actually rotating part of the hinge. I let the JB weld set overnight, then I repeated the same procedure to attach the bottom shell, and again let it set overnight. It is very strong. You can see how this looks on the left picture of post #37 above when it was all done.
Depending on what your gauntlets are actually made of, JB weld may not be the best choice (I'm not sure how well it works on plastic, for example), but it is great for a metal / wood epoxy combination, which is what I have.