Some of the Armada covers of the 1960s weren’t credited.  I am not an expert in the technicalities of art by any means, but to me it looks as if all these covers are by the same artist.

Who that was I’m not sure.  I’ve wondered if it was Elisabeth Grant or Constance Marshall, but haven’t come to any useful conclusion!  If you do know, or have any theories, I’d love to hear from you.