[GTALUG] Selectively restoring WordPress posts from old SQL dump

I have a bunch of WordPress blogs sharing a database, which seemed like a good idea at the time. Now I have a bunch of posts that were overwritten at *some* time in the past by bad data, but my backups are good. My backup testing works perfectly well for complete replacement, but I don't want to do that - I want to cherry-pick for one blog of several, and only replace posts that existed in November with the same IDs in today's database, but leave everything else alone. Does anyone have any thoughts? Right now I am hoping not to have a couple of terminals open and try to manually run UPDATEs with copy-n-paste, because that seems rather error-prone. Thanks! William