Imaginary story.
Imaginary story.
On the page between page 5 and page 6 of the previous story sequence.
Imaginary story.
The second panel of page 3 is reproduced directly from "Superman's Mermaid Sweetheart!" from Superman (DC, 1939 series) #135, page 10, panel 5 (with new script, background, and Superman headshot) by Wayne Boring and Stan Kaye. (Information from Christoph Melchert and Allen Ross via the GCD Error Tracker.)