Chase's most famous (and infamous) novel was his first of over 80 - No Orchids for Miss Blandish published in 1939 by Jarrolds of London. In the next 70 years the book was retitled, revised, bowdlerized and censored by publishers and modified by the author to produce at least five versions. It also has been filmed twice - a low budget British in 1948 and under the title The Grissom Gang in 1971, directed by Robert Aldrich.
The Harlequin edition is one of the modified ones originally published by Jarrolds in 1942. There is a Harlequin reprint with April and June 1951 dates and one with April, May and June dates. I don't know if there is a printing with April and May dates only.
The sequel is The Flesh of the Orchid, first published in 1948. The Harlequin edition was reprinted in June 1951.
Harlequin 108 - April 1951
Harlequin 108 back
Harlequin 111 - April 1951
Harlequin 111 back