When it says Libbys on the label
If I had a dollar for every time someone sang that jingle to me when I was young, I could have retired by the time I was 30 years old. I was very glad when they retired it. Hadn't thought about it in years but then I ran across this site of vintage ads. This predated that jingle.
I think it predates all these ads too but it may be somewhere on that site. It's kind hard to navigate these live journal things. You have to view the archives through the sidebar and the tags. I actually arrived there following a link to vintage pin-up produce ads. But cool site if you have the time to fool around with it.