KABtronics has an all transistor nixie clock kit for sale. It is still a work in progress but it looks to be nearly complete and a few kits are available for sale. This definitely looks like it would take some time to assemble. It is made of 215 Transistors, 518 Diodes, 472 Resistors and 101 Capacitors. Wow.
Mathew Beall sent in a video of his assemble. Be sure to check it out:
I purchased onne of these, when I have a moment (or a couple of thousand), I'll video putting it together. ;)