I think this is the coolest clock ever...used but working DG7 tubes and a transformator cheap, one from Mullard and one from Phillips. Other CRT Cathode Ray Tube types can be used; you can even rip one from an old and maybe dead oscilloscope, then you also get the powersupply and stuff. If you are lucky the deflection amplifiers also work :-) Then your own home made Scope Clock is soon up and running, good luck. Link.
Homemade Scope Clock