I agree with others I have seen this type of cap construction, exterior and interior, on Bundeswehr Marine peaked caps....
Prost ! Steve.
"The German Army is the perfectly adapted, perfectly running Machine. The difference is that the Germans are organised with a view to War...with the cold, hard, practical and business-like purpose of winning victories."
G.W. Steevens - The Daily Mail (1897)
KM are a tough area to collect, due to a number of factors. First is that most are unmarked OKK visors, so it is difficult to attribute to a specific maker. Second is that the early BM visors are similar to the KM ones in construction. Third is that a lot of them are French made.
The ones that are actually maker marked are few and far between.
NEC SOLI CEDIT