I'm still interested too. Ian you have more software experience than I have. I do have the Texas instruments sinks working but I need some help with the seven segment switching to make an alphabet. I used Arduino for mine. Torston here's the datasheet: www.tube-tester.com/sites/nixie/dat_arch/Numitron_RCA_01.pdf
I love these tubes... I'm glad someone wants to make something with them still. I asked a few people that made before and none had and PCB left.
the problem with the datasheet is that I can't find information of the diameter of the tubes directly above the socket and the height of the smaller area above the socket. My hope is that they could also fit into my "Thomas" clock case. I asked Ian but still wait for the information.
It would be great if they fit the existing case...