280GE waterpump replacement - advice needed

Major waterleak from somewhere invisible around the lower end of the waterpump led to me abandoning the G in west Pembrokeshire over the Easter weekend. Owing to lack of serious tools (only a 1/4" drive small Halfords set  and a 17mm socket available) I didn't get any further than the picture and still couldn't see where the water had come from.   I am trying to find out what might need to be replaced and what is involved in waterpump replacement as the gasket is the primary suspect (orange coloured material) but can't find anything on this forum or the Three Pointed Star.  Now back home 300 miles from G have this morning priced various parts with my usual local dealer.  This contained some surprises including £89 for a two inch long length of rubber hose between the thermostat housing and the waterpump as shown on photo (part no MN900271 042012). Unreal, even with G Tax.  Worst possible scenario looks like £450 for parts alone although £43 recoverable on return of water pump. Has anyone any experience of waterpump replacement??  I hope to return to Wales in a week or two for further dismantling to get to the area of the pump.

WDB46023227060781  with 110(99420006882) motor