So this is the story. I built the main carcass of the box and that worked ok, I added the psu and that worked ok, but then I got ambitious and tried to fit too much in, it didn't all fit, so there's been a revamp. The compromise I made is to move all the switches and power supplies into the main box out of the lid, giving more room for the wiring.
For this revised stage only
14 x 20cm, 13 x 23cm, 2 x 23cm
40pin male header
4 x illuminated rocker switches
1 x DPDT centre off rocker switch (can be just DPDT)
USB Hub 4-way with switched supplies. A common model is shown in the pictures
USB type B panel mount socket
2 x buck/boost voltage down convertors, adjusted to 5V
1 x buck/boost voltage up/down convertor, adjusted to 12V
1 x buck/boost dual rail voltage up/down convertor, adjusted to 12V
Various matrix board bits, I've used offcuts and rejects instead of new perfect board
Lots of multistrand wire, rated for 3A or more.
Negative voltage generator
555 timer IC
Resistors 4k8 and 33K 1/4watt
Polyester capacitors 22n, 10n
Electrolytic capacitors 33u and 220u (30V plus rating)
2 x 1N4001 diodes, but any small rectifier diodes will do.