R.A.J. Walling The Corpse in the Crimson Slippers (Hodder & Stoughton, 1936)
My copy seems to have come from a circulating library in Murray Bridge, with the dust wrapper glued to the boards for eternity. This is fortunate, otherwise I might have missed that R.A.J. Walling is "The ingenious Mr R.A.J. Walling". It is, however, repeated inside, with a list of his ingenious works:
The Corpse in the Crimson Slippers is certainly not lacking in ingenuity. It has all the trimmings of the locked room, "copper-bottomed, A 1-at-Lloyds case for suicide", improbable forensics genre and also manages to cram in secret agents, false beards, dodgy financiers, counterfeit bank-notes, mysterious scientists, plucky house-keepers, fly-fishing, country-house living and Early English Architecture. From the moment the hero got on the train carrying his "Banister-Fletcher though he weighed about three pounds", I was hooked. Have you encountered Banister-Fletcher's A History of Architecture on the Comparative Method (still in print, 20th edition, since 1896)? It is the sort of encyclopaedic guide to architecture that could keep one entertained on a desert island for a decade. I was quite sad that it didn't become the murder weapon.
Source: George P Landow, here.
Words repeated too often (and directed at the emotional French: "For an instant Tolefree feared Thibaud was about to embrace him. The danger passed."): persiflage, popinjay.
Rating: period flavour 8/10, literary merit 4/10.
If you liked this... here's another out of print stinker.