wyager:
Wow-lots of wires! Thankfully, the IN-14s I'm using (as soon as USPS feels like delivering them, they've been in the US since at least the 26th) come with long leads, so hopefully it will just be plug-and-play.
Cool. I had to solder leads onto the sockets. There's four 74141s and two 595s on my breadboard. I'm slightly amazed I got it all working pretty much first time (I'd got digits 8 and 9 mixed up on one of the nixies). It'd have all been easier if I could make my own PCBs but that's something I've not got round to yet.