I just finished up a new guitar assemblage that I'm calling "The Nemo 20,000." It reminds me of something Captain Nemo might play in the Nautilus on a rainy day. ;P
I bought the guitar off of eBay for about $5. I sanded it and coated the entire guitar with copper and iron acrylic paint. Added some dabs of rust and copper patina to age it.
At Goodwill I found a cool oxygen gauge which I stuck at the top of the guitar. That piece gave me fits. It was too heavy to glue, so I had to drill a hole and then seal it with Liquid Nails.
JoAnn's craft shop had some neat little wooden pegs that looked like rivets.
There is a piece from a cheese grater with a handle so Nemo can really "shred" when he wants to.
Finally I put an exhaust pipe on it and a temp/humidity gauge and a couple of plastic firemen to watch over the whole flammable mess.
You can click on the image to get a little closer look.