[skb]

I can't find a reference to "The Perfect Murder" but he did write a short murder mystery story called "The Perfect Plan".

Edited to add: In Appendix 6 of the JH Companion, it's mentioned that American scholar Frederick Ott was writing a biography (should be published by now?) and that a "fully comprehensive bibliography of Hilton's works, both fiction and non-fiction is in preparation by Sandy Weiss of Illinois". Hope that helps.