Yes, the Klingle character (Jamie Farr) was a straight guy drafted to serve in Korea. In those days homosexuality was one of very few outs afforded to otherwise healthy males. So part of the show was his endless attempt to get out on grounds of homosexuality. Alas, no one paid much attention to poor ole Klingle, knowing he was straight,
BTW, the term ‘gay’ wasn’t used in those days other than to denote a happy person, and I can’t remember if ‘straight’ was used to denote hetero.
I'm of the older generation when "gay" meant happy and joyous. Neither of those adjectives can be applied to the twisted perverted deviants who have co-opted that word.
Not only do I want my country back, I want my word back. I refuse to use the term "gay" to characterize the abomination of homosexuality.
As for your question, back in my younger days, I don't ever recall "straight" as a noun to denote heterosexuals. There was no need to distinguish normalcy with such a label. As I recall, the word most widely applied to homosexuals in the 40's and 50's was "queer".
At birth, Almighty God made us all normal sexually. Those who became homosexual did so by willful, deliberate choice. A homosexual must repent of the sin and, after regenerative cleansing through the Blood of Christ, sin no more.
I don't think Klinger was presented as gay, but as a cross-dresser.