3-band parametric EQ

[Wizardof_Oz]

I'm about to build this EQ based on the PCB from THCustom as a kit from Musikding. Hopefully somebody here has built it already and can share some experience...
I couldn't find any wiring information whatsoever, can someone share wiring instructions for this EQ or pictures from a finished project?
Additionally I have following questions:
- the PCB and instructions show no hint in which direction the bridge rectifier SMD should be soldered on the backside of the PCB. I guess the plus pole of the rectifier goes towards the Vcc eyehole next to it. Can anyone confirm?
- is it possible to run the pedal with 18V on the input side. Would the components cope with this higher voltage?
- Musikding added an optional 20k resistor instead of 33k for R23 ,,for gain". Nothing else mentioned...What effect does this have?

You can tell that I'm not an electrical engineer, at least I can solder...
Thanks for your support.