The Mighty Marvel Bullpen, circa 1970.
Of course, the idea of the Bullpen was mostly exaggerated at this time, and so some of these folks must have come in specifically for the photo. But still:
[Unknown], Gil Kane, Stu Schwartzberg, Gerry Conway, Bill Everett, Herb Trimpe, Marie Severin, John Verpoorten, [Unknown], Roy Thomas, Larry Lieber, John Romita, Morrie Kuramoto, [Unknown (Allyn Brodsky?)]
This will be updated if more people are identified…