Really awesome picture from a 1969 comics convention. Lots of familiar names, but all so young and so well dressed! You can click on individual sections of the picture to zoom in and see the names.

I am pretty sure that the man standing between Verpoorten and Schwartzberg is MarK Gruenwald

I thought that, too, Jay! But i figured if he hadn't already been identified, it must not be him, and then i looked up his date of birth (1953), and that guy doesn't look 16!

I believe that's Al Hewetson. There's a photo of him in that 1969 Bullpen photo feature that was in FF Annual #7.

http://kirbymuseum.org/blogs/dynamics/2010/12/22/1960s-marvel-bullpen/

Wow. They look pretty much the same. Great picture by the way,

I emailed the Marvel Bullpen photo link to the guys running that Convention site, and based on it they think the guy at the far right in the back standing over #24 is probably Stan G.