He had at least three published novels. And their dust jackets are gorgeous. I can't imagine many of these are still floating around. So let's post them here, too, for posterity.
Drum & Monkey
"A novel about a dealer in second-hand oddments, and his ambitions for his young son."
The Burnt Man
"Man escapes his past and starts life anew in the west of England."
via Between the Covers Rare Books Inc.
The Third Day
"Humphrey Daine dramatically remakes his life and loves."
via Amazon (It would be great, though improbable, if a better version of this dust jacket was available somewhere.)
Drum & Monkey (1929) and The Burnt Man (1930) were published by Faber and Faber. The Third Day was published in 1930 by Horace Liveright.
1. Before he married Ruth Vernon Manning and became a hyphenate, his birth name was George Rawlings Sanders.