Hi Bruno,
Interesting helmet!
Do you have some picts of the back of the wappen (loops or threads?) and of the front of the shell without wappen?
I think I see some curious traces in the leather shell near the non grommeted hole #-o
The brown liner seems to show that this helmet has been produced late 1915 while still using brass fittings.
Is the rear spine ventilated?
It´s also interesting to see that this helmet is still wearing some chinscales. I always though, as Larcade wrote, that FAR60 EM helmets wore the leather chinstrap starting 1915 #-o
Philippe