Start by reading Heinlein’s “By His Bootstraps” (1941), and then read this one. You’ll enjoy both and stretch your mind around the first ex nihilo idea that we’ve spotted in comic books. Note that the half blueprint itself does have an origin, and you can trace it’s timeline from that origin to the past and back again. It’s only the concept expressed in the blueprint that has no origin.

NoMan, a cloaked hero with the power of invisibility, was a member of T.H.U.N.D.E.R. Agents, a team of superheroes first published in 1965 by Tower Comics. I didn’t read them until 1976, when I bought a black and white reprint comic, Uncanny Tales, when I was in Stirling. I don’t know whether any of the other agents time traveled, but NoMan did in both of the issues of his own comic (in Nov 1966 and Mar 1967).