Old Radio Bits? – Make a raygun!
While this is not 100% Steampunk in style,this is still quite a nice bit of re-purposing of old bits and gubbins.

For the handle of the gun, the creator used an old super-8 movie camera into the handle for the raygun. The flash mount is an 8mm projector lens which forms the barrel. Vacuum tubes from a vintage radio go into the other parts of the gun. This raygun certainly captures that a nice vintage look to show off and this gun does provide one heck of a visual blast.
More photos of the construction process maye be found here: