The meeting at the end of the episode of where Kelly and Alexander (Bill Cosby Robert Culp, respectively) run into Sheldon Leonard
is self-referential joke (Alexander saying he didn't 'admire the violence' in Mr Leonard's shows -I Spy (1965) being a massive hit at this time - and it was full of violence... as anyone who'd just watched this episode would agree), as Mr Leonard was the creator and executive producer of this series.
Near the end of the episode, Munoz tells Scotty "you are a comedian", which, of course, Bill Cosby is.
The comic book Kelly's reading just before Sean Christie's telephone call is "Konga" No. 14 (June 1963). The Charlton Comics series was based on the British giant-ape film Konga (1961). In an interesting parallel to the episode's plot, the cover copy of the issue Kelly is reading states, "... Only Konga stood in the way of their 'MASTER PLAN.'"
Kelly and Scott meet Sean Christie atop the awe-inspiring Pyramid of the Sun at Teotihuacán near Mexico City. It's he third largest pyramid in the world.