The present watch was made by the renowned firm Ed. Koehn in Geneva, often signing their watches "H.R. Ekegren".
Henri Robert Ekegren (1823-1896) was a renowned Danish watch, clock and chronometer maker and watchmaker to the King of Denmark. He worked for Urban Jürgensen, Henry Golay, Joseph-Thaddeus Winnerl and Adolph Lange before setting up his own business in Geneva. In 1857, Ekegren founded together with Ferdinand Westermann a factory specializing in the production of chronometers which was sold to Edouard Koehn in 1891.
Edouard Koehn or Ed. Koehn (1839-1908) started his horological career in the workshops of Patek Philippe as a watchmaker. In 1891 Koehn took over H.R. Ekegren, keeping the company's name and the founder as chief engineer until the latter's death in 1896. The firm, as of 1908 managed by Koehn's son Edouard, specialized in the production of flat or extra flat watches and complications and the improvement of the retrograde display mechanism. It appears that the company was dissolved in the mid-1930s.
James Emmett Caldwell (1813-1881) began his career as an apprentice to a silversmith in Philadelphia. In the early 1830s, he opened his own watch and jewellery shop which became known as J.E. Caldwell & Company in 1848. The company retailed watches made by the most celebrated manufacturers, notably Ekegren and Patek Philippe.