Unfortunately the fakes in felt helmets are getting pretty good. Be careful of marks that look like this. The real check is to see right off if the helmet in question could have been in IX Corps. This helmet and one other with the faux markings reversed could not have been in IX Corps.
Many fakes have a leather edge that goes all the way around. These are regularly light in color. I call them the chocolate colored trim.
Fake Felt
Lots of fakes here. There is even a web site that tells you how to make a felt spiked helmet. A collector friend's husband visited a factory in England where felt helmets were being made in the 1970s. There were also some fakes that came in through the Eastern bloc. Those were allegedly squishy. The standard filzhelme is quite hard.
Unlike most felt helmets, this felt helmet is not stiff, it is more pliable than others