Lot 10416 – 1905 (3rd Nov.) chemical experiments, an appendix sheet marked confidential from the De La Rue Day book

1905 (3rd Nov.) chemical experiments, an appendix sheet marked confidential from the De La Rue Day book signed by Hugo Muller (De La Rues consulting chemist), showing three vertical columns of different coloured Victoria head dummy stamps, the first column marked « Cancelled » the second marked  » Cancelled and partly cleaned » the third marked « Cancelled and Cleaned »; a very rare an highly important archive piece.