Great photo: I love them all.
For the best curls I recommend goo old fashioned pin curls with setting lotion (I just use bobby pins and apply in wet hair) - but yes, these would have been done with hot rods and rags. How successful the curls are depends a lot on your hair, with fine, straight hair being particularly reluctant to curl.
I have naturally wavy hair, much to the delight of every hair dresser I've met. It takes curls easily and will hold them for days - hot rollers also work well. As a child my mum once put rags into my long, straight blonde hair for Nellie Olson ringlets when I went to a fancy dress party at the height of "Little House on the Prairie". Oh, they were wonderful, like bouncy springs.
If you are blessed with silky, straight hair, you're the envy of everyone who resorted to straighteners as the style is often in fashion.