Thanks!
The end of the barrel is a genuine Heiland Flashtube.

The little button control looking thing is indeed from an antique flashlight.
The base "gun" is a "Powder Actuated Tool". The handle, before I smoothed out the grip section, had the brand name, either AMMV or something similar, and "Studgun" on it. The pawn shop had it labeled as a "ramset". It was missing parts as you can see in it's original condition above.... but it whispered "Blaster" to me. It was heavy too... I'd guess about 8 pounds before I gutted it.
The Barrel is a Heiland, and the gap between the outer shell of the studgun and the end of the barrel was filled with JB weld and then sculpted. The greeblies under the barrel are a brass air hose junction, mated with a copper pipe fitting and the round retaining nut left over from my truck's old busted headlight switch(from when I converted my Truck to the Phoenix). The angled "box" greebly behind that is a key off one of my old worn out keyboards. The "T" section on the reciever is a curved scrap of 1/8th inch aluminum, two small aluminum blocks, and 3 small steel woodruff keys. The various screws are random machine screws I had. The detail above the "BlasTech" is a piece of aluminum scrap, as is the scope rail. The scope was also scratch-built with aluminum tubing, a knurled retaining nut from an old toggle switch, a wheel bearing out of one of those aluminum scooter wheels, a lense out of a broken pair of mini-binoculars, and the plug from some old electric scooter charger.
Just in case anyone wants to build their own
