There are 8 because it's a "Countdown Duration/Elapsed Time" clock from Apollo 11
Your description makes sense as well as the diagram in the manual. Thanks.
I'll get the kit with the wifi module for sure.
The clock may or may not work as it is. I suspect it does not, and the tubes are probably fine. However, because I've tracked it's historical significance, I want to preserve the inner workings and retrofit the case to run my clock.
I'm curious about the logo on the top right corner of the countdown clock. I can't quite make it out in the picture. Is it a Collins Radio logo perhaps? If so there's a pretty good chance it was made just down the street from where I live.
Look into it later when the dust is clearing off the crater.