Simon.
I guess we a have a few more items we can elaborate, starting with the aux. luboilpump and its 2nd task, fueloil transport. If you look at the system below you are able to trace the red encircled valvechest and the fuel filling line with the coarsefilter. If you look towards the galleydoor stb side, you find the fuel filling line with the fairly large black valve wheel disappearing towards the floorplates, just like the luboil filling line on the port side of the door, howewer the coarse filter is missing. Then you go to u historia engineroom page and one of the last pictures there you`ll find the coarsefilter (clearly showing the design) and the valvechest A underneath the heatexchanger, (circular large tube), from this valvechest it is possible to follow the suction and dichargepipe up to the pressure hullside and across to portside and the pump. This is quite a deviation from the pipesketch.
Tore