I've modeled out a rough 3D case interior in Fusion 360. I didn't want to go too far into the 3D design at this time since I am still settling on some equipment and hardware details but I did get started on two things. 

1. I did a first draft sketch of the front panel using my placeholder interior. 

2. I began the process of arranging both panel and interior components that I knew I needed or wanted to include. 

Taking stock, Inside I need to accommodate need a minimum of 2 usb hubs (one for 2.0, one for 3.0) , the pi, the SDR's, power pack, port and patch connections, cable guides. On the panel I have an ambitious layout with lots of patch ports.

My desire to have 2 screens is fading as I am bringing certain details together and the realization of the limited space that is available. I have started to gel on a bracket system idea for the solar panel that I would have to design and 3D print. The panel would ride inside the case and add a bracket as a mod to the case exterior. I think I can integrate it in a way that's super low profile and doesn't compromise the case, i.e. no penetrations. Since that is a novel design element, I'll keep logs on the various stages of development.

Also potentially on the chopping block is a way to slide my additional battery pack into the deck. The product I am considering is the Geekworm Raspberry Pi 4B/3B+/3B X735 V3.0 DC 6V-30V Width Voltage Input Power Management with Safe Shutdown

A mockup made up of other mock ups. The round blue items are arcade buttons that have the same dimensions as the ports I am considering so I had the model and just threw that ion there to give me a general sense of size, Also, the speakers are from Adafruit but are slightly smaller than the ones I have, so I just threw those in there too. The small circles at the bottom are RG6 connectors for an amp, 3 different attenuators, antenna ins and outs and HackRF One clk in and out.