Fantastic info.
One has to be careful about the definition of sales - sometimes, the song we knew was huge was “never released as single”, etc, so didn’t really get any sales! But I am very aware of all these songs - back as a youth, and still today. They were huge and they are often played right up to today on the more general stations.
For all of these songs, the quoted sales level (i.e., n/a, Gold, Platinum) is for the single. In some cases, the album on which the single was located also was certified Gold or Platinum as well.
The big shocker for me was that American Pie didn't break 500,000 in sales as a single, or an album. Candidly, that's not one of my favorites but you cannot deny the impact or popularity. I read that although singles are often shortened versions of the original, they chose for the single of American Pie to be all eight+ minutes, splitting it across the A and B sides of the 45.