Publisher: Fawcett Gold Medal (1963)
At first I wasn't sure if I could credit this cover to the Dillons, but if you look closely in the lower right hand corner, you can see the distinctive looping double L of their signature.
An online archive dedicated to sharing the work of Leo and Diane Dillon
Source information posted for “Don’t Take Me For Granted, Dear” by Mark Schoer
Thanks for the information, Martin!
Source information posted for “He Can’t Be Dead, He Spoke To Me” by Rona Jaffe
Thanks for the information, Martin!