The cover of this Sexton Blake Library thriller shows two men with guns and stashes of cash, as if a bank job were in progress. At no point in the story does anybody point a gun at anyone. The main characters are all financiers; some are greedy, but none are gangsters. And the blonde beauty on the cover doesn't correspond to any woman in the book with a significant role. That aside, this is a moderately entertaining whodunnit marred by the author's need to state everything in detail at least three times. I suspect he was over-writing to make up the word quota since each number had to be 60+ pages long, actually about 60,000 words, a full-length novel. The content here would have been more appropriate for a novella. Sexton Blake doesn't appear until more than half-way. He is assisted by Tinker, and hampered, one might say, by the 'sooper', Venner.
Link to the book:
Sexton Blake Library S3 322