Now that I've seen Mo Marcus's work (he signed the first story in this issue of Charlton's Go-Go—#6, Apr/67), I would agree with Mark Evanier that Marcus started off the story in Dell's Monkees 1, the subject of my last two posts. The no-name gimmick here makes sense given Mark's suggestion that this was meant for a Monkees story at one point.
In his comment on the first of these posts, Mark posited that Dick Giordano and company stepped in to salvage Marcus's work on Monkees 1. I still think that Ross Andru was one of that company. I see Marcus's figures in the Dell story (and will admit that the Andru style resemblance there is a coincidence) but just don't see Marcus's style in the faces.
But it sure wasn't José Delbo!