No photos but have attacked the sump, timing cover, bell housing and bell housing adaptor castings with marine clean. Pretty pleased with the results, still some spots of muck and grease to get off but will need a pressure washer and wire brush to get them.
Cleaning was prompted by crystal flakes growing off the castings, the engine must of been through some serious salt early on in its life. The stuff is still there in places and will take a wire brush to remove it.
Am going to keep the castings with the painted engine block under my desk at home for the moment, its better than the damp of the shed. Will get around to sorting of the roof out and applying a coat of waterproof sealant, then the de-humidifier will need to do less work.