The present watch combines several unusual features, most notably the relation between the historic backgrounds of the coin and the key.
The head of the male key, showing the portrait of the Duke of Wellington and the inscription "Waterloo", is possibly an allusion to the fact that Arthur Wellesley, first Duke of Wellington, and his allies vanquished Napoleon Bonaparte's Grande Armée at the battle of Waterloo in 1815. Following the defeat, Napoleon was imprisoned and then exiled by the British in October 1815 to the island of St. Helena in the Atlantic Ocean, 2,000 km from any major landmass.
Dated 1865, 50 years after the Battle of Waterloo, the French Empire 50 Francs gold coin with the portrait of Bonaparte's nephew Napoleon III combined with the Duke of Wellington key could symbolize a commemoration of the victory's 50th anniversary.
Another particularity of this watch is its extra thin movement. This so-called "Bagnolet" or "inverted" calibre with cylinder escapement with the gear train underneath the dial instead of in the bottom plate was developed around 1840 by Philippe-Samuel Meylan. As of the mid 19t century, these ultra thin movements were also used in gold coins. The flattest Bagnolet calibres do not exceed a millimetre and a half in height, insignificantly less than the present movement and its width of approx. 2 millimetres.