Hi Old Guy, the long finger came into the equation on this job so I have only just got around to removing the offensive part.
Your understanding of the cooler assembly is not quite correct. The oil cooler centre bolt that comes down from above and runs through the water I/O section can be removed from the pedestal without removing the filter as this mounts onto a separate thread protruding from the base of the pedestal. So... its possible to remove the top section and leave the pedestal and filter but you have a serious fight with the hoses. The 'right' way, as I see it is to remove the lot, loose plenty of coolant and why not change the oil as well while you are half way there with the filter removed.
A tiny but persistent leak had given the top of the cooler section a surface resembling the surface of a very old orange, a bit worse than just cosmetic. A few coats of paint rather than 500+ bucks fro a nice shiny part. Thanks anyway for the reply as it was one reason to tackle the job.