Split Charge System - Advice Required

Hi - I bought my Scout as an ex South West Ambulance Service rapid response training vehicle. It's great - drives spot on and I have 25 pages of service history. Most of the kit had been ripped out and I have fixed almost all the mess that the decommissioning had left. I have left the leisure battery and split charge system in the boot until now. Can anyone look at the photo and tell me what some of the items are? I would like to remove anything that was for lights/sirens/comms, but would like to keep whatever is needed to keep the split charge working and run some lights, a usb or two, and a 12v for a fridge all off the leisure battery.