But you're right, the theme has been used before. The Gideon Stargrave issues way back are the first instance I can recall.
Hmmm. Howso? Do you mean his writing or his time-travelling?
I was thinking of the fact that King Mob is Gideon Stargrave, the writer. And the stories depicting Gideon Stargrave the character may be stories written by Gideon Stargrave the writer...and may be describing things that happened in reality (or not). At least, that's how I'm remembering them. I should probably go back and look at them again.