Not a Panzerschutzmütze and no Third Reich connection whatsoever: It's an armored troops beret of the Federal German Army [Bundeswehr] (ridiculously "decorated" with an RZM label by some faker) and a generic triangular cloth from a first aid kit.
That explains why I could find no such beast after an hour of searching.
It makes me feel better because my gut was saying no no no no... but most everything these folks had was right as rain.
People who sell such obvious fantasy fakes are either stupid or dishonest. In either case, they can not be trusted and should be avoided.
LIFE'S LOSERS NEVER LEARN FROM THE ERROR OF THEIR WAYS.
the RZM tag is on the piece of triangular cloth.
Doesn't change the nature of the Bundeswehr beret, of course; but I may have been too hasty with the black cloth.
It would appear to be a HJ scarf, although I cannot tell whether it is a genuine one or not. Perhaps Bob Coleman could comment on the RZM tag?