This is a set that came to me in April 2017. It appears to be a mint and untouched set from the earliest period of the inventor's set.The set was sourced in the UK. The intact guarantee slip dates it to Sept 1916. They were announced in the Sept/Oct MM, although evidence shows they may have been out earlier. The issue price was 7s 6d but this one has 10s penciled on the back. It could very well have been old unsold stock or the factory made so many in Sept of 1916 during the 1st introductory run that the stock from then lasted for several years? The set was not priced at 10s until 1919. This set also has some of the "economy" parts from the wartime era it was produced in. It also has the rare brass sprocket chain! Enjoy!