More progress the past couple days. Got the new engine on the stand and started tearing it down to verify condition and get it ready to accept the new pistons. I've attached photos of what I've found so far, which is an engine that does in fact seem to be factory new. All internals have a light film of oil on them.
Take a look at the photos of the first piston I pulled: #2. To me, the rod bearings look new with zero wear -- do you all agree? I'm marking these as they came out because I've heard their specific location should be the same when they are re-installed -- maybe this is less important having no wear?
Also see the photos of the crank -- again, looks like no wear to me -- and the bores (same, minus some very light corrosion at the very top that should be scuffed off). The piston looked slightly gross when it came out, I think the rings probably slightly corroded. They cleaned up very well with a little carb cleaner, but will be subbed for 9.8:1 pistons.
Here's my question: I think that every indication shows this engine is basically as-new, as advertised. I plan on replacing seals based on age, but is there any real need to remove the crank from the block and take it down to a bare crankcase? At this point, I'm thinking about just putting new standard size pistons and rings in, reusing the bearings, replace all seals, etc. Then rebuild my existing (used) head from the old engine and put it all together.
Any specific reason that I should be dropping this engine off at a shop for machining work or tolerance checking if all appears as-new?