In 1926 Bonebakker receives the special commission for creating a royal gift for the city of Amsterdam in honour of its 600-year anniversary and the opening of a new wing of the town hall. In the new workshop on Tweede Wetering Dwarsstraat, master smith Maarten Zwollo creates a 16-piece dinner set, which, amongst others, contains fruit bowls, jardinières on a plateau and candelabras. The total weight in silver is 74.48 kilos.
Then, in 1929, the big stock market crash also has an impact on Bonebakker and the company faces hard times that will last until after WWII.
In 1943 Carl senior hands over the management of the company to his sons Carl and Adrianus. They decide to secure their entire stock and collection and sit out the war. The transport of the goods to a secure place is done in the greatest secrecy: the valuable silver is taken away by hand-pulled carts, covered by canvas. Another part of the silver stock is hidden in the cellar of the building of Het Witte Paard, behind a pile of rubble. Even though the Germans raid the place, they never discover the silver.