We looked at the crank to determine if it was dirt or something worse. Sadly, it's something worse. The crank has a burr on it. Whoever built this engine dinged the crank with the rod bolt while installing the rod. Now we know this engine would have eaten itself eventually if we had just fired it up. We're going to tear it all the way down and inspect everything before sending the crank out to be polished. We might even throw some modern parts at this time capsule.