Bear's GU ST build-up

After running the power from the second battery to the rear I installed a fuse box. I decided on the spot in the tail light cavity, it's still fairly easy to access:
Attachment 16015
I've powered up the merit socket and cigarette lighter socket on separate fuses (so if one circuit has a problem I will still have cold beers!)
The other fuse is for the reverse light/work light. I fitted an on/off/on switch. One position it works as a reverse light, and the opposite position it is on constantly powered by the second battery. Here's the switch:
Attachment 16016