I came across a blog article last year entitled: Josef Jakobs - The Last Execution at the Tower of London. The author of the blog, Robert Walsh, outlines the story of Josef Jakobs. The account, while quite readable, suffers from several factual errors, inconsistencies and spelling mistakes.
Date of execution - Walsh correctly says that Josef was executed on August 15, 1941, and then later alters that to August 14, 1941.
Executions at the Tower - Walsh correctly notes that 11 spies were executed at the Tower during World War I, but later notes that prior to Josef, the last execution took place in 1747. Prior to Josef, the last execution at the Tower took place in 1916 (World War I spy - Ludovico Hurwitz-y-Zender).
Nationality - Walsh states that Josef was a Luxembourger, which is inaccurate. Josef was born in Luxembourg to German parents and was a German citizen.
Money - Walsh says Josef was equipped with £500 in forged notes, also inaccurate. The currency that Josef brought was turned in to the Bank of England and exchanged for new notes. The money needed to be available for Josef's court martial, and after that took place, the original notes he brought were destroyed. Had they been forged, the Bank of England would not have issued replacement notes to the Security Service.
Court Martial - a typo - Josef's court martial took place in 1941 not 1940. Sergison-Brooke did not preside at Josef's court martial, that honour went to Major General Bevil T. Wilson. Sergison-Brooke was the Officer Commanding, London District.
2.5/5 - Several inaccuracies and spelling mistakes distract from the overall story.