It was never published, though aspects have appeared in a number of series since, most notably Kingdom Come. This is what Alan Moore would have written for DC next if they had agreed to renegotiate the Watchmen and V for Vendetta contract, in light of the new market realities. They didn't and Alan chose to no longer write for DC Comics. In the words of Bullseye, this is what you could have won. Image, decades later, by Moore collaborator, Don Simpson.
Other time travelers might very well include Tommy Tomorrow and even maybe an earlier version of the Time Trapper himself, who might very well provide the help these stranded travelers need to return to their own times. It strikes me that amongst these travelers there might also be Space Ranger and Jonah Hex. This might even be an opportunity to return Jonah Hex to his original western continuity where we know he will eventually end up according to previous DC history.