This is Thrilling Wonder Stories for October 1952, cover by Earle Bergey. The ISFDB entry for this issue is here. I extracted this version of the cover from the issue as preserved at the Internet Archive, along with this piece of interior art by Virgil Finlay, illustrating Wallace West’s novel The Bird of Time:
You can download and read the entire issue from the Internet Archive.
So that’s what he got up to when he wasn’t being Kid Flash!
Pulp writer surely makes a fine alter ego for a superhero, because people will expect you to keep odd ours and behave in eccentric ways.