Neat Ranchero! I've never see the turned metal interior trim pieces in anything other than a GT before. Very interesting. Not sure if that's original. Only reason I say that is because I'm sure the steering column / wheel is not original. They should match the rest of the interior, and be ginger color, not black.
^^^ You think maybe it's the remnants of a car wash or hosing something off? Looks like there's some water in the bed also.