I can't think of an incident when Golden Age superman was able to see people naked.
I wonder how Lois would have felt about it if it was possible
This cover from Superboy (aka young Superman) demonstrates that he is capable to see through layers of clothes, at least when worn by another male. There is no reason to believe that he could not also see through women's clothing when he would want to. But considering that Superman follows a very strong code of ethics, it would be very unlikely that he would abuse this power for his own sexual pleasure (and besides, the censors of that time wouldn't have allowed it anyway).