There's a whole stretch of WORLD'S FINEST covers, mostly by Win Mortimer, showing Superman, Batman and Robin together, even though they're not in the same stories inside.
It seems like it'd be fun to tell the unseen stories behind each cover...
The #31 cover can go so many ways. Are they unlicensed (perhaps dangerous?) figures? Are they official merch? Are the heroes happy or upset? I think there was a Superman Animated episode where Toyman sold Superman action figures programmed to steal... so many options.