Your Jet Pack looks just like a GM item to me. This what I have too.
Mine is heavy (fiberglass) strangles me to death and tends to hang to low, probably because the back of that sucker isn't curved (like the real deal), therefore don't respect the natural shape of spinal column … but I’m might be wrong about this and it’s me. I have to rethink my harness system from A to Z.
Otherwise, great start mate! I wish I had such a nice costume … :cheers