Of course it's true that Braithwaite's advanced age was simulated through makeup. My post was really commenting on two ideas. First, as a kid, my friends and I thougt of certain people as OLD. For example we thought Dr. Smith on Lost in Space was OLD]. In reality, Jonathan Harris was just over 50. I thought of Professor Robinson as played by Guy Williams as being relatively young, yet he was closer in age to Harris than he was to Mark Goddard (Don West). When I started watching Barney Miller, Fish seemed pretty ancient, and yet he's not that much older than Barney, Hal Linden.
The second thing I was kind of obliquely commenting on is how are perceptions of age change. As a kid, 46 seemed pretty old. In fact I've have been surprised to learn that Guy Williams was almost that old during Lost in Space. I certainly don't feel old now.