With a tip of the hat to Les Troyer and Richard Klyce, who wrote up alternative versions of this concept in Mainsheet and gave me the idea:  Just completed the first of this winter's projects, which was to redo the primary fuel filter system on our '85 Mk I (after 10 years of frustration with the original setup).  
    The older C36s like ours came with a massive Dahl filter (apparently way oversized for the needs of these engines, according to the two writers above)  located under the port settee, with barely any room under it to drain water or fuel, and a total PITA to service the filter.  Luckily, I never had to do this at sea, but even in port changing this filter it was always made a mess, accompanied by a lot of unpleasant speech. 
    Instead, I removed the tilt-out utensil drawer that is to starboard of the galley sink (we could never use it anyway because it was too short for our utensils!) and located the filter there (I reused the door) -- see 1st picture

I put together a system with two Racor 120As as the primary filter, with 10 micron filters, with 3 way valves so we can switch from one to the other if the first gets clogged, without having to shut down the engine.   There's also a vacuum guage plumbed into the common output side, so we can monitor the filter's condition (some time digging through small brass fittings in the parts bins at a good plumbing supply will enable making this a very compact unit, so that there's amble room to access and replace the filters).   The filters and valves are mounted on a piece of starboard, that's attached with angle aluminum stock  --  see 2d picture.

I fabricated a catch basin for the whole system (using a spare fridge door insulation box that I cut down to size) and lined it with an absorbant mat to catch any drips.    See 3d picture. 

The Facet pump now pulls from the primary filter (rather than pushes in to it), and is located lower down, reachable through the small door that is below the galler sink (that is used to get to the galley through-hull);  I mounted the pump to a block that I pre-epoxied onto the little angled section of the galley cabinet with captive bolts.  There is sufficient room there to get under the pump to drain it and service the strainer basket.    In truth, the pump could have fit in the same area as the two filters were it not for the fact that I have a vacuum loop for the primary bilge pump line in the left hand (i.e. aft) area of the cabinet that I installed years ago, and I didn't feel like relocting it (maybe some other day).