EH Octaver Multiplexer doubts

[jbvidigal]

Hi guys
I've been looking for a nice octave down pedal to build.
I found the stuff for an Octaver Multiplexer. Ordered parts and the whole shabuzzam!
However... There are some issues I'm nor sure of... Maybe you guys can help me out on this one!



In the layout image, there are some "unfilled" connections with no indication whatsoever. What are those for?
A second thing comes up when some other unfilled connections are indexed with, however, nowhere indexing it to! They are called up with letters: B, C, D, H and I. Another letter is present in one of the pins of the transistor. What are the letters referring to? And maybe less relevant, why is letter G "attached" to that pin!?
The last thing that I don't understand is where is the switch for "SUB ON/OFF" connected to? And what switch is it?

Thanks for all holy patience with noobs like me!

[jbvidigal]

Well... I guess the letters must be for the spdt switches! However I still don't get the 'blanks'! Voltage measuring points? But what for?
Anyways... I'm gonna try building another EH-OM that I found in aron nelson's library! The PCB is smaller! Maybe I'll do both just to get the experience and an idea of the difference!