Sister, I think I've ready everything Plum ever wrote, including many of less-then-steller early novels and short stories.
His characters and stories had as much as depth as tin foil, he used the same four plots over and over, and his characters never left their artificial bubble of the 1920s. Yet, other than Pterry perhaps, there's no other writer, English or otherwise, who could consistently raise the most cliched and dog-eared plot point into euphoria with one of his crystalline perfect phrases or lines of dialogue.