Can you think of any other topical references on this great, but sadly short-lived, detective series?
The building where the McKells and Monica Gray live in "Too Many Suspects" is described as a "new building". The actual building at that address was indeed built in 1947.

That Hollywood episode was a good one. Lots of great references to classic actors.
Several of the Ellery Queen novels were set in Hollywood, so looks like the producers decided to do a Hollywood episode as well (although that episode isn't based on any of the actual stories aside from the setting).
A few of the EQ novels were set in Wrightsville, which is why the producers decided to have the one episode set in this fictional town. I wish that they had adapted the novel
Calamity Town
(the first novel to be set in that town) instead of going ahead with their own Wrightsville script. It was one of the weaker and more predictable episodes, while
Calamity Town
is an amazing book.
The only two episodes based on EQ literature are the pilot episode and
The Mad Hatter Mystery.
Another great character is Frank Flannigan, the loud-mouth reporter in a few of the episodes. Too bad he and Brimmer never appeared in any episodes together.
This show really should have run for another season or two. On the other hand, at least they did a lot of episodes during its run (as opposed to
Columbo
, which only had a few episodes each season). Since Jim died in 1979, they would have had to find another actor to play Ellery if the show had continued for a number of years. But one or two more seasons would have been nice.

Jim Hutton (1934-79) & Ellery Queen

I liked the episode when Richard and Ellery Queen were out in Hollywood to see the filming of one of Ellery's novels at an, apparently, very schlocky film studio.
When Inspector Queen got a look at the older, slightly out-of-it actor portraying him in the film (veteran character actor Noah Beery, I believe), he really bristled, saying something to Ellery like: "Couldn't they have gotten Brian Donlevy to portray me in the film?"
Sadly, I don't think that Inspector Queen ever did get to see some actual film stars out in Los Angeles like Bette Davis, Alice Faye or even Huntz Hall!
PS John Hillerman was an absolute hoot as the "slightly" pompous Simon Brimmer on "Ellery Queen." I loved watching Mr. Hillerman as he portrayed the unfailingly supercilious and condescending radio show host. It's no surprise that the creators of "Magnum, P.I." thought of Mr. Hillerman to portray the equally haughty Jonathan Higgins on that long-running detective series. "Ellery Queen" should have had a much longer run on television, imo.

In one episode, Ellery referenced one Bette Davis film.
Radio plays were a big deal in the forties, and those were mentioned in all the Simon Brimmer episodes.

Jim Hutton (1934-79) & Ellery Queen