The Avenger was published by Street & Smith and written by Kenneth Robeson, a house name used by the publisher. Paul Ernsy is largely accredited as the main writer of the series. These covers were created in the 1970s and published by the Warner Paperback Library. They were illustrated by George Gross and Peter Caras.
Wow, nice job! I will certainly do what I can to help you out.
the ones by gross are clearly signed by him
the other early ones are by peter caras a protégé of james bama