A specific date I cannot find. Not in 1936 nor in 1937. In the Deuster -book he neither mentions a specific date.
It must be 1938 anyway, which is the most plausible, as in the Uniformen-Markt magazine from March 1, 1939
a one-liner says: all of the motorized Gendarmerie are to be supplied with a Sturzhelm (which is the leather helmet).
Maybe someone here can tell more!
"Wir sollen auch unser Leben für die Brüder lassen" (1.Joh.3.16):
zum Gedächtnis Wilhelm Schenk. Er starb fürs Vaterland am 13. Juni 1916
Thanks for the info, that's a start anyway.