[clay68c10]

I wouldn’t get worried about the exhaust yet, you live somewhere humid and the temp was low enough that it could just be condensation.
Get your temp gauge working, get an IR temp gun to verify it. Might be time to get or rent a coolant system pressure tester.
All those cooling system parts are old, and they will end up failing on you. I’m betting that after you fix the radiator, the heater core will let go.
Not being a dick, just speaking from experience. I like my old cars to be as dependable as my new ones, that means a lot of wrenching time initially. Eventually you get over that hump and you have a nice driver.