Very nice indeed. I need one of those wave generators for my classroom. Has anyone seen one before?
The closeups were very revealing.
It looked to me like the rods and center wire were a bunch of 1/8" brass rods and a piano wire down the middle. Probably drilled in one jig, set in the next jig to align the rods and thread the wire. Then a smack with a small punch or ball pein hammer at the brass/wire junction would make that permanent.
The trestle assembly was interesting but it looked like the piano wire in the wave portion just sat on a cross piece of wire in the trestle.
It would take some experimenting to find the right diameter of piano wire, but should not be very hard to do build one. Obviously, the motor with the wheel on it was home made as was the damper and the fixed clamp.