OK, here's the current case I designed & 3D printed, for a one-box solution without cables everywhere.
It includes a standard Pi battery (Like this:
http://amzn.eu/fcGY5lz), and a SMA pigtail antenna mount + antenna from here
http://amzn.eu/6UoJcMx for the RTL-SDR.
I removed the case from the GPS dongle to make it fit. There is support in the case wall for the GPS board.
The battery lasts about 2.5 hours, and it has a standard micro-USB connector for charging.
Rather than an external USB to micro-USB cable for power, I soldered the wires internally, via the switch.
The lid is dual-colour 3D printed. I tried the same with the case for the lettering but the results aren't great.
For updating you can get to the ethernet socket with the lid removed - I did this without issue today.
If anyone is interested in one of my cases, I'll list them on ebay in a few days. I'm currently waiting for proper sized M2.5 pillars for mounting between the Pi and the lid to arrive, and will probably sell it as a kit with the pillars, switch, screws etc.
And if anyone would prefer a version without the battery, i'll work on a version like that soon.
Any suggestions to improve it further welcome. I've already recessed the power switch by a further 2mm in the design, which will be in the next print.