How did your viewing go? Was this your first time watching "The Return of Charlie Chan" aka "Happiness is a Warm Clue"? The second title is interesting, as there was a flurry of "Happiness is..." sightings in the mid- to late-1960s. The Beatles had a song on their White Album from 1968: "Happiness is a Warm Gun." Very possibly (probably) an influence on the Chan title.
I hope that you folks enjoyed "The Return of Charlie Chan" with Ross Martin.
As a die-hard Chan fan, I own a DVD of this made-for-TV film. I thought the writers and producers (Jack Laird and Gene R. Kearney) did a respectful job of bringing a connection from the old film series to this modern-day Chan film.
Regarding the acting, I would put Mr. Martin's interpretation of Chan slightly above that of Roland Winters and J. Carrol Naish.
For me, the film (and the story) worked. I liked it.