Checked some sources. The name is Pierre Didier-Drevet. There is some indication his son was involved in the business.

He held a patent for d'Eureka-Canon-Plume, Oct 10, 1899. He was located at 5 & 11 rue Villeboeuf, in St Etienne. He had won expositions in Paris 1855 and in London 1862, most likely for percussion guns.

Pete

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