The Eiclone monoblock board uses half a 12AX7 as the voltage gain stage. Does this mean that you'll end up with a bunch of half used up 12AX7s? Au contraire....
The first 9A diagram is what we would see looking at the bottom of the PCB. Pins 5 through 9 are wired. Pins 1 through 4 are floating. Lucky for us, rotating the tube 180 degrees (or in this case, the tube socket) lets us access the other half. Clipping the pin 5 leg off of the socket and jumpering the old pins 4 & 5 (providing power to the new pin 9, the CT) complete the procedure. Voila!
Shannon