RE: Fire Extinguisher Placement
There is a reason that Westfalia placed the OEM extinguisher where they did,
the same reason that in an office  building they are  in the hall or by the
door. They are located near an escape route so that you move away from the
fire, get the extinguisher, and then if safe reenter the area to use the
extinguisher. They most likely place to have a fire in a well maintained
Westy is not the engine compartment but the living area, the kitchen.  So
the extinguisher is by the door so you can get out, then grab the
extinguisher and put it to use.  If it's behind the drivers seat, a perfect
place to grab and head for the back for an engine fire, you will be SOL if
you have a grease fire on the stove, you will have to go closer to the fire
to get to the extinguiser.  The ideal solution would be two, one where the
original is/was and another behind the drivers seat.  I have two Halon
extinguisers, one by the slider and a small, hand sized one that is loose
and normally sits on the corner of the sink when camped and stored with the
teapot in the sink when the stove top lid is down for traveling.  And my
fuel lines are in good shape (but I'm still thinking about adding a fire
port in the back just in case).