set me straight: help understanding "blocks" in schematics please

Hello, simple nube question here, first a bit about myself, I am a circuit bender of keyboards, I have a good general understanding of electrical components and their functions. I recently have been commissioned to build a pedal to control the rotation speed of a rotary speaker (a "Motion Sound Gas Pedal," no longer produced). I feel I am up to the task and have found the proper schematic which is attached to this post. I understand the upper portion of the diagram just fine but am somewhat new to this and puzzled by the detached section at the bottom. C1 and C2 are used heavily, I am wondering how to attach the bottom portion with the top.
I get the DPDT switch and the jacks, I am just wondering how to hook up the bottom module with the top, i.e. which side of the polarized capacitors (C1,2,3..) to connect to and how to handle their multiple implementations. I assume current runs from left to right here (+ to -), but whats the deal with C4 and C2 being in line for the amplifier jack? Sorry if my questions are confusing or don't belong here, please clarify this for me.

If the PRO-3 module were shown, I think it would be easier to grasp the overall layout.

The upper circuit is for controlling the PRO-3. It has no direct connection to the lower circuit. Both circuits are enclosed in a single foot switch.

Evidently there must be 2 cables going to the PRO-3.

OH, okay I see. The "C's" on the bottom don't denote capacitors at all, maybe just stand for contact..This looks to be cake. I'm excited for my first perfboard project. Yay! The switching jacks seem to be kind of an odd addition, this is just a speed pedal, there is an instrument input on the PRO-3 already...Thanks for a clear answer to a silly question, now lets see what else I can make seem more complicated than it actually is...