I am very sorry to have to report the death in December 2021, of Robert Georges Claude Ernst-Metzmaier, who was, believe it or not, the son of Rodolphe Ernst-Metzmaier.
Robert was 97. His father, designer of the Renault FT in 1917, lived to be 98, dying in 1985. I had the good fortune to correspond with Robert about his father's role in the design of the FT, and he was most helpful, providing me with documents and photographs. I also met his (IIRC) great-nephew, who was studying engineering in Liverpool.
Something that emerged was that a man often seen in photographs of the FT prototype and described as Rodolphe Ernst-Metzmaier is not him. We haven't identified the man, but he bears no resemblance to Rodolphe.
"Sometimes things that are not true are included in Wikipedia. While at first glance that may appear like a very great problem for Wikipedia, in reality is it not. In fact, it's a good thing." - Wikipedia.