http://www.thingiverse.com/thing:52252
I bought all the goodies to make a nice Nixie clock from Taylor Electronics, but I didn't have a nice case for it. It took me about 6 hours to design, cut, and re-cut parts until I had something I was happy with. I disabled the I2C master on the first TES 1361 SmartNixie board and replaced it with an Arduino Nano board connected in the unused RTC connector on the bottom of the backplane board. I poll the GPS RTC board via I2C to get the time and then send command over the I2C bus to the SmartNixie boards to display the digits.
Laser cut parts from 1/8 acrylic (The stuff I bought from Home Depot ended up being 2.2mm thick and not 3.175mm(1/8") so this drawing was designed for 2.2mm, but that isn't hard to change.)
Order these parts from http://www.tayloredge.com/storefront/index.html
1 x 1392 - 6 Digit IN18 Clock Backplane
6 x 1361 - SmartNixie IN18
1 x 1375 - SmartNixie GPS RTC
1 x 1364 - SmartNixie HVPS-H
1 x Active GPS Antenna
1 x Power Plug
I ordered my IN-18 tubes from super-gene on ebay: http://myworld.ebay.com/super-gene/
6 x IN-18 tubes
12V power supply and Arduino Nano can be ordered from Amazon here:
http://www.amazon.com/Wall-Adapter-Power-Supply-12VDC/dp/B006GEPUYA
http://www.amazon.com/Arduino-ARD-NANO30-Nano-v3-0/dp/B003YVL34O
Arduino Sketch: