I have a new review of a novel from the '70s up at Black Gate, this one concerning L. Sprague de Camp's THE FALLIBLE FIEND: www.blackgate.com/2024/07/06/a...
I get the impression that for whatever reason -- perhaps because it's a prequel -- this novel is less well known than the other Novarian novels. (I have heard good things about those other Novarian book, actually.)