I just became aware of the Rockford episode, This Case Is Closed, has in it Jude Farese and Susan Jacoby both from An Exercise In Fatality, and also James McEachin from Make Me A Perfect Murder and Etude In Black.
And of course Columbo's car has a cameo appearance in the Rockford Files pilot episode, "Backlash of the Hunter". RF used a few moments of film from "Columbo - The Most Crucial Game" for an establishing shot. Both shows are Universal productions.
Sounds good!
I noticed Sian Barbara Allen is in an episode.
I saw the one with Jude Farese yesterday, he plays a henchman who keeps hitting Rockford. Still haven't seen part 1 of the story where I suppose Susan Jacoby appears.