I just started V3 of my new radio box I hope to have completed in the next few days. I am using a Otterbox 1000 (nice and small) and I am adding the test fire buttons to the lid of the box.
In order to make this work I had to use smaller firing boards and as such I used a prototype board that I am testing to see how it works.
I am not sure how I will seal the box but I want to be able to replace my interface board for the ribbon cable so I will proably use the blue gasket maker I got from Auto Zone I used to make my deck seal gasket with good success.
I will utilize a simple pump switch to keep the radio box small in that I will use a firing board to trigger a sealed automotive relay ($4) that will sit outside the radio box near the pump. This will not only save space in the radio box but will cut down on the amount of expensive 12G silicone cable I have to use in the ship.
For the throttle I plan to use the banebots ESC and encase it in epoxy and run it from outside the radio box, once again to save space and cut down on silicone wire. This will keep me from having to add the larger motor output cables to the outside of the box. I will just feed the reciever leads out on the ribbon cable. I dont currently have a bane bots ESC so I will utilize the same output pins to trigger sealed relays that I will store outside the radio box near the motors.
This should be one step closer to the modular box I am wanting and help with overall wiring reduction. The other main objective is to make a drop in box that is compatible with any of my ships allowing me to mix and match at any time.
Pictures are below:

