Visor Cap Help

[swatmaster68]

Want everyone's opinion on this. Allegedly originally obtained in 1988, from a German Vet who stated he was a Policeman in Hannover and Berlin during the war. Apparently it's size 56 and the celluloid diamond reads: Sonderklasse, Wilhelm Schwarte, Berlin G 2, and what may be Schillerstr. 22. I cannot provide any better/closer pictures because the item isn't mine. Any opinions will be appreciated. It apparently also comes with a handwritten letter from the vet gifting the cap. Thanks a lot!

[swatmaster68]

My question was answered in another thread. Thanks for looking though!