Rb26 rebuild

Hi guys got an rb26 came in knocking bottom end big end no.5 destroyed. Hole in the piston. Side walls scored bore needed and full rebuild. Simon the pistons is that the sandblasting on top from detonation ?also the bore can i ask the pics you see a long line done the bore i cant feel it with my nail would that be ok if there was no other damge to use again like that? But the tops of the bores are scored and my nail can feel it. Would a hone cure this or is it a bore next size ?