First appearance = was suppose to be in Steel, the Indestructible Man #6 (probably would have been cover-dated December 1978 / January 1979?), but that series suddenly ended after issue #5.
The story was then included in the book Cancelled Comic Cavalcade #2 (Fall 1978), but not in a finished format:
A few years later, story and art that would have been used in Steel, the Indestructible Man #6 was incorporated in All-Star Squadron #8 (April 1982):
And for more on the "DC Implosion" and "Cancelled Comics Cavalcade", see:
* https://en.wikipedia.org/wiki/DC_Implosion
* https://www.comics.org/series/2439/
* https://comicvine.gamespot.com/cance...ade/4050-2942/
among other places.