I'm betting your 'touch' on the telescopic tool & caliper is not positive enough PB.
What I mean is your adjustments are a whisker lose.
I'd measure the rest of them before thinking about a re-build.
Pick up a cheapo compression tester.
That’s what I’m leaning toward. I already have a compression tester, but I wasn’t using that right either! That is actually what started this particular adventure.
I had already ordered new head gaskets, so it is at least worth measuring all the cylinders as best I can, reassembling and re-testing.
I will see if I can get one of my mechanic friends down here to show me what I may be doing wrong with the telescoping cylinder diameter gauge. I know it is hard to get it centered and squared up, but I would expect an error like that on my part to give an over reading, not an under. I have it right on top of the piston in the center.
I’ll take a picture if I can.