Dewald supplied trucks to the french government during the war, but also in the years after they had substantial contracts for military use and from building contractors. As the article in CU says, they must have been prisoner of their own concept and when the time came to modernize they missed the boat. Charles Dewald is considered as the inventor of the hydraulic tipper. If you look up his name in google patents you'll find a patent of a hydraulic ram, US 1.237.309, where oil is supplied through hollow journals. This is obviously done in order to avoid the use of a hose, which back then could not withstand the high pressure. The hydraulic system of my truck has disappeared but you can steel see the holes where the ram was fitted and the pto on the gearbox.