Thanks, yeah, I went through them one by one. There were about 20 from a deleted account, like I'd mentioned, and a surprising number (of OLD posts) that were marked as -3 in queued. I changed a lot of them to 1 so they'd show up in the approval queue and I could approve or delete them. Who knows… maybe we missed them at the time.
Got the list down to about 40, not counting the 30-50 spammy posts by bots that will be removed if they don't register (they won't) within the next week or two.
So, really, most of the old stuff was just old guest posts that may or may not have had the right flags in the database. But, every action except changing some of those columns was done in the UI on the site, either in the ModCP or the ACP, so whatever needed to be done to affect other tables I'm sure was done.
Thank you for taking the time, @bfarber.