It's tool marks where the tire changer scraped off the finish.Looks like someone used some sort of bead-sealant glue on previous install. Or is that just corrosion?
Under most circumstances I would say you should replace valve stems also. Any shop is legally bound to do so. I just figured since it was just replaced 1 year ago, and will need another tire in a year anyway, thought it would be fine.
Guess that's what I get for thinking :surprise:.