Final base assembly:
The nuts holding the false floor down were hampering the position of the chargers, so I put 1/4" ply blocks in place to match the position of the chargers' feet (picture). Then it was time for velcro. At first I wasn't sure if velcro would hold things securely enough, but everything is in so tight that it turned out to be more than sufficient. I put velcro on the bottom of each charger (the soft part) and place the hook part on the floor of the case. This way the chargers won't scratch any future surface they may be sitting on (pictures).
The fourth picture below shows all the chargers in place. The wiring isn't super neat with balancing boards and charging cables strewn about, but the case serves its purpose--I just close it can carry it to the car.
I finally held my breath and connected the PSU. Bingo, all the chargers turned on. It's hard to make out in the picture but the bullet lead next to the PSU with duct tape on it is the 3 to 1 harness lead. This plugs into either the PSU or an external cable to clamp to a deep-cycle battery (picture).
The case stores away neatly in my workshop next to my transmitter case.
Next up: pouches and ties for the PSU power cable, the external DC lead, various battery adapters, balancers, etc. I haven't quite figured out this part yet. Any suggestions?
Ben