I tend to agree with you, James Finn. The Baby-Boomers and Gen Xer’s I know do display some of the behaviors you mention.
To use myself as an example, I present masc, and if you met me you wouldn’t immediately think I was gay, but if you spent significant time with me you might begin to think I was.
I don’t suppress behavior or language. I don’t have one type of behavior in public and another one in private, I just “am” and let any chips fall where they may.
I don’t usually engage in campy language, but over time, the occasional “puh-lease”, combined with the patented gay eye-roll would probably lead an observant person to think I’m gay.
It’s a small tell, but useful because it’s these small things that other gay men pick up on that makes gaydar work.