Thanks for those reviews, Gene. I've not seen any of those films but it's interesting to read about them. It seems that the property dropped from A to B, then sort of B- later on. I've never read the story but I've heard a radio version with Jack Benny,--yes!--and he's quite good. It has humor but it's not played for laughs.

Seven Keys To Baldpate is one of those "properties" that seemed to get remade in various forms and media over the years, and in this reminds me of Trent's Last Case, The Most Dangerous Game and The Monkey's Paw. These were favorite tales from another era. Their literary status (so to speak) seems "unsure", as they're not quite classics and yet were once highly popular. Good yarns, from a time when storytelling wasn't yet a lost art.