On Mork & Mindy, when Mearth showed up and was supposed to age backward, I took this to mean that Jonathan Winters was so old as to be near death in real life, and so he was being very generous by being on a television show for us.
On Different Strokes, Mr Drummond had a fiftieth birthday party where he got a bit of ribbing for being old. They made fifty sound old enough to be sort of…sad to contemplate.
On Gilligan’s Island, The Skipper seemed old. I think his light hair seemed gray all over to me.