DC almost certainly wouldn't have any ownership stake (why would they?), but there are two hurdles I can envision, which would require more research than just knowing the story is there.
First, if the story or whatever it was published in--"zine," for lack of a more period term, I guess--had a copyright notice, then it was automatically renewed and extended.
Second, if the "zine" wasn't easily available, the Copyright Office might not consider it "published" in the technical sense. In that case, it would have a Life+70 copyright term.
In either of those cases, it'd be controlled by the Siegel and Shuster estates, rather than DC. So using it wouldn't be so much "stickin' it to the Man" as "stickin' it to people who the Man stuck it to."