Cleaned out the radiators last week. they weren't too bad.
The coolant level might have been low before hand. It's not something I check normally as I've never had the temp drift past the 8 before. With 92k on the pump and thermostat, I figure it's probably best to replace them both anyway. I'll post pics of them when I tackle this one. Probably June 7th-ish.
ETA: The coolant tank is original and still white. I don't notice any moisture when I lift up the carpet in that area.