"If I were a woman as I am a man" is a striking clause, but IMO it does not hint at homosexuality; rather, it suggests a man who is so secure in his masculinity that he can put himself in the place of a woman without compromising it. Such an attitude would be hard to imagine in (say) the US of the 1950s, when most straight men were very much exercised to prove they were not queer. It is perhaps easier to imagine now.

I cannot think of any old songs that actually refer to homosexual feelings or relations. There are a few bawdy songs that celebrate what Freud called polymorphous perversity, e.g., "The Pioneers":

Great joy they reap from tupping sheep
In sundry bogs and ditches,
Nor care a damn if it's a ram --
Those hardy sons of bitches.

I don't know how old that one is.