From what you are telling us, I don’t think you are going to like me or my answers. Sorry if that is the case, but based on my experience I must be brutally honest. First, you need to get a new service shop. These guys are just guessing, as they have you looking for parts before they have even opened the engine. Not a go sign. Second, I asked for serial and engine numbers, which they should be able to supply you very quickly. You’ve provided only half of the needed numbers. Third, you asked about crankshaft and cylinder walls, again they are guessing they are OK. If you are seriously considering repairing this engine, dump these guys first. On your question about scoring, only a very close look and trained eye can give you a quality answer. Piston scoring, cylinder scoring, bearing scoring, and journal scoring are all different. Here again is where you need to go to a qualified tech to get a quality answer. Plus I would never put a used part in a rebuild unless I had absolutely no other way to complete the job. In this case being penny wise and pound foolish will bite you in the butt everytime.