Aviation Michel (Strasbourg, France) existed from 1926 – 1928 . The A.M.16 aero-engine looks very much the same as the Vagova car engine. It was designed by Pierre-Henri-Edmond Vareille and used the same desmodromic valve distribution.
The Frenchman Vareille patented different desmo-systems (Classification: Group 1A; 4 and 8A systems). Source pictures: Patented Systems
According to Gilles Fournier, an authority on the French brand “Amilcar” and the French Cyclecars, the used system in the Vagova is a group 8A embodiment for sure. In his new book (to be published in 2012?) Mr. Fournier will reveal a picture of the used desmo-system.
The used word “Desmodrométiquement” (in 1926) is very special and not common. Claude Bonjour used the French word “desmodromique” already in his patent from 1893.
Drawing left is the SOHC engineblock from the Vagova.
Photo right is from the Michel-Aviation AM-16 aero-engine with the same desmodromic valve gear (design Vareille). See text below. “Une commande desmodrométrique” = “Desmodromic control”
Source textfragment: “Les moteurs à pistons aéronautiques français” (Volume 1), by Alfred Bodemer and Robert Laugier, published by Editions Larivière in 1987.