The PSU mounted in the case. I've left room at the rear of the transformer for the mini XLR connectors.
The wires on the left, terminating in spade connectors, attach to the on/off switch in the upper part of the case.
The bare wires top right, will be soldered to the mini XLR power output socket, prior to closing the case up.
The grounding post to the left of these wires is the drain for the power output screening ground and is attached to the earth wire of the 3 core mains input cable.