I visited my buddy Dan this week and he used his router machine to shape a pattern for me. After we were done working in his shop he opened up his music room and showed me some of his custom stuff.
Here's his custom one piece Mahogany fret less bass:
This chunk of Mahogany was being used as a "floor" plank in a mason's scaffold when he discovered and rescued it.
The shaping was done with a 7"angle grinder.
He made the bridge from scratch out of some sheet steel, a small tube, and some threaded hardware.
Someone told him he needed a truss rod so he used a pilot drill and installed a threaded rod that is anchored to the head stock plate he fashioned from a chunk of aluminum. He adjusts the tension from an short access "channel" in the back of the body with a coupling nut.
He found some tuners and a pickup on an old throw away instrument. The strings probably cost $30 so I'm guessing he has well under $100 in this custom one piece Mahogany bass.
He let me play it. It plays like butter. Loads of fun and great balance so the neck just floats in your hand.
He also showed me one of his many fifty dollar Keytars:
I thought about telling him he should buy Trillian to use with it, but I figured he's already doing great without any ideas from me so I just sat back and listened to him jam. ;-)
Good times.