The Fat Man was a 1945 – 50 ABC Radio series starring the rich voice of J. Scott Smart as Brad Runyon the overweight detective also known as The Fat Man.
Each program started the same way, with the announcer appearing to let us in to a secret. “He’s walking in to that drugstore . He’s stepping on to the scales.” The sound of a coin dropping, and then a mechanical voice: “weight 237 pounds. Fortune: danger.” The music rises then fades. “Who is it? The Fat Man!”
Incidentally, Jack Scott Smart did himself at the time of the series weigh in at 270 pounds!
Unfortunately there are only about 12 of the US version still available. The others that you will hear on RUSC are the Australian version I think there are about 40 of these. They are superb quality but I'm uncertain who the star was. It may have been Lloyd Berrell, but I can't be sure. If you know "who is it?" then please do let me know.