The adafruit Feather M0 WiFi arduino board has turned out to be the perfect board for the Master Control Panel. There are many pre-made ‘wings’ that can connect together through a common set of pins, including the OLED screen on the top of the MCP, and the servo controller.
Since the board diagrams are available from adafruit, I was able to use their template to create a printed circuit board and have it made by OSH Park. The MCP I/O Wing plugs directly onto the bottom of the other board, allowing me to neatly plug all of the components into it with tiny board connectors by mill-max.
The breadboard. 
Finished PCB with the I/O connections. 
Finished PCB with Diodes, and tiny inverter. 
All of the components, read for soldering.
I experimented with a very small surface mount component to invert the signal going to the camera. It replaced five through-hole components, but it is only ~5mm square. It was a pain to soldier, but I only had to do it once, and it allowed more space for more I/O ports.
The board has an ethernet port and I/O connectors for the camera connector, USB, 12V in, Analog Out, reset and power buttons, and the long range radio upgrade that are part of the case. The board can be reconfigured with a different arrangement of I/O pins, and used as a receiver at the other end of an ethernet cable connected to the MCP. The Ethernet routes power and data to I/O pins and other Feather boards..
All of the buttons and connectors that need to be wired to the I/O ports on the MCP PCB 
This port connects the MCP to the BMMCC. 12v mains to power the Camera, sBus data for camera control, and 5v out to power the MCP. 
All of the I/O connections were tested before the connections were insulated, and the case assembled. 
It’s a mess of wire, but it’s silicone wire so they are all very flexible. 
The electronics fit snuggly and securely in the vinyl and aluminum shell. 
Without building the case in 3D, there would have been no way to get clearances around the electronics. 
The MCP is ready for a life on set. 
I learned a lot from the first, wired, controller. The flexible silicone wires made assembly much easier on the WiFi MCP.
