I've already tossed the bags for the brass parts, but I got them at Lowe's in the plumbing/sink section. There's a thread that lists the part numbers, so it should be easy to find. Search "ROTJ gauntlets". I couldn't find the exact air compressor fitting, so I faked it. The look is still pretty close. 8)
The nozzles are Radio Shack part # 278-188. They're PL-259 UHF Coax'es, which is why they're so big.
They run close to $6 each.