Nice helmet. Congratulations.
With its particular shape, in a single shell, and its edge hemmed with a small steel wire, it is an manufacture "S. Schneller et Cie in Breslau". These shells were made from the same mould, in sheet iron, brass and, more rarely, Duralumin (copper and aluminium). On this model, the cap is made of black patent leather, and there is sometimes black felt at the bottom of the shell to insulate it from the cold.
Here's a "brass" found on a dig
An identical one from Württemberg, also in brass. When the visor is made of brass or aluminium, soft metals, a reinforcing bead runs around the edge, as on leather shells. Not on a sheet steel shell.
The same model in Duralumin :
Two types of tip fixing:
---1--- washers and folding lugs.
---2--- Openwork teller specific to this brand
And Schneller's black-finish liner.