Clue Club was launched early due to the US Open tennis tournament, which CBS held the rights to at the time, and would otherwise hold back the start of their children's lineup for a week or two. While this was a novel idea, it was never duplicated, due to the simple fact that Clue Club was not renewed for another season. As we've documented before, the series was reworked into edited reruns under the title, Woofer & Whimper, Dog Detectives, as part of Skatebirds the following year, before reverting back to the original title and 30 minute format in 1978.
In "The Case of the Lighthouse Mouse", the Club has to clear their Uncle Salty (Paul Winchell, also the voice of Woofer) of the theft of some priceless jewels.
At least we know both of the boys, Larry (David Joliffe) and D. D. (Bob Hastings) were old enough to drive. Not sure about Pepper.
The biggest difference between Clue Club and Scooby-Doo was that this was more of a procedural crime drama, with the dogs acting as comedy relief. Should it surprise anyone that Whimper (Jim McGeorge) was actually smarter than Woofer ever gave him credit for?