I interpreted the fact that he was reviewing multiple copies of the same text as him searching for Galileo’s notes, but I suppose it’s possible that the motivation was the possibility of discrepancies between printings.

Nothing all that exciting, just pleasure from finding a photo in a local newspaper of my great-great-grandfather’s (approximately, I don’t remember the specifics at the moment) car being pulled by horses out of a local river, or researching a family name I found in a cemetery and finding interesting tidbits about their history.

Probably the most impressive effort I stumbled upon was a woman from rural Indiana who collected (and typed up) thousands of pages of local history & genealogy in the mid-20th century. Was interesting reading personal accounts of Morgan’s Raid, for example.