Ah-ha! A Singleton Pound classic adventure in one Lord Northcliffe’s halfpenny specials – or as AA Milne put it, not so much a penny dreadful as an ‘alfpenny dreadfuller! Singleton Pound also wrote as Oliver Merland (Sexton Blake, The Human Mole), his real name, and Colin Collins (The Blinding Light).
This is a typical rip-roaring adventure which has stood the test of time. My lateness in commenting today is due entirely to getting sucked into this.
Link to the book:
The Union Jack 183 - Don Manuel's Diamond