Iwas looking on the bright side after seeing the great condition of the top-end; a few bits of metal floating around the crankcase would have settled to the bottom of the sump and stayed there, right?
I mean, I saw no evidence of carnage in the cam bearings, so the oil-filter was doing its job. Nothing to worry about, so the next day I walked into the workshop with a clear head and a job to do.
First thing was to remove the pistons. I have some small Snap-On long nose pliers that I have had for ages and that are great for removing wire circlips. Just grab the circlip near its end, then pull down