[leegreen]

Are you going to tear it the rest of the way down? Pull a bearing cap or two to inspect? What to the bores look like? Valve seats, stems and guides?

The reason I ask, that block surface, piston tops look like more than break in hours to me. But maybe that is what you get from many years sitting.
And it may not be relevant if everything is in good shape.
The engine is clean enough inside to assume it has at least been apart in recent memory.

If I was preparing that block to put a new head gasket on without going any further:
plug oil passages with wound up rag
protect lifter alley from falling debris
stuff rags into each bore
clean block surface with scotchbrite pads by hand working around, away from holes holes
pull rags with a twisting wiping motion.
get everything as clean as possible & put it back together
degrease and paint once it is buttoned up