I was in the autozone the other day and saw a tool that I'd used several times and not thought twice about. It is a clutch plate alignment tool on the "help" isle. They are made of plastic and cost about $7. With light modification, this could be made into a wrist rocket. If you REALLY want a metal one, find an old PTO drive line from a tractor and machine it down, but it's gonna be heavy. This plastic tool (even if it had a solid brass head) would still weigh less than one pound. As far as darts go for the gauntlets, get some dremel bits (green beveled stone type) and just paint them. If they need to be sharpened, put em' in the dremel and grind on some metal. I like to save a buck when I can and try to pass on what I learn.