redesigning a PCB in Kicad - 15/03/2023 05:50 EDT

I need to redraw this diagram in Kicad. Currently, the board is on a single PCB, I would like each function to be on a single PCB connected to the next in a modular manner like the attached image. As per the attached picture, I would also like to change the flat cable insertion with an adapter. Each module must be 60mm x 60mm and use non-SMD components but the classic through-hole ones.