I have already tested :
type 7B :
10/1939 at Erprobungsstelle : all is ok
11/1939 at Wilhelmsahfen + ride to England : all is ok
type 9B :
10/1941 at Erprobungsstelle : all is ok
11/1941 at Lorient : all is ok
type 9C :
10/1942 at Erprobungsstelle : all is ok
11/1942 at Saint Nazaire : all is ok
So far so good !
