I started off making the barrel pretty much how Volpin made his, using pvc and Apoxiesculpt
For the rear chamber, I glued together 2- 4" couplings and cut them down the middle. I made it an oval tube by adding a strip of styrene on each side as seen here
I made the rear shell out of insulation foam that was glued together into a block, then sculpted into the shape I need with a knife and 60 grit sandpaper. I sealed this with Smoothcast resin before skimming it in bondo and sanding smooth
The barrel "nozzle" was made from a pvc reducer and a 2" coupling. the center band and lip was formed with Apoxiesculpt. The center detail was cut from an end insert for a roll of butcher paper !
I made the center light tube from an acrylic rod for rolling out clay, bought from Michael's and made the caps for mounting the l.e.d's from pvc adapters.
I made the rear panel fron 1/4" acrylic, painting the inside surface black. I bought the drawer pull as a handle from Lowe's.
I cut the claws out of styrene by hand
The ends of the claws were made from styrene also, the gaps filled in with Apoxiesculpt
I mounted the front led board into the barrel nozzle, and the speaker into the main barrel body
here is a mock up with trim plates installed
All put together, I used bendable wire as armature for the rubber tubes to help them keep shape
I still need to print out the proper decals for it
The lighting and sounds came from a kit from a member of the RPF named Crix (not Volpin), It has startup, shutdown and the 2 different sounds for each color, along with an idle sound.