Detective Comics, Vol. 1 #479 (1978)

If A Man Be Made Of Clay.../True Heroes Never Die
If A Man Be Made Of Clay...: Before Preston Payne can complete the mechanism which will restore his humanity, Batman confronts him and all of Clayface's efforts go up in fire and smoke. True Heroes Never Die: Hawkman and Hawkwoman return from Thanagar only to find that in their absence, the Midway City Museum has been taken over by a man named Anton Lamont. Mavis Trent walks into the Hawks' former office to greet them just as Lamont is telling them how they've been fired.
Release Date: 1978