Post war I believe due to the pin. Odd that the front is perfect with that amount of rust on the reverse.
P.S. Nice to see you in the pink Andreas!
Searching for anything relating to, Anton Boos, 934 Stamm. Kp. Pz. Erz. Abt. 7, 3 Kompanie, Panzer-Regiment 2, 16th Panzer-Division (My father)
The color is also thick and the helmet way to massive for any wartime pieces I saw. Maybe overpainted? That would explain why the rust is only on the back. Under the swastika are also small rust spots under the finish. Pin is definately not wartime made.