I have one similar (to the one without Semper Tails banner) but without any markings, so could be any of the regiments that had the white metal guard eagle and fittings.
Michael
Hello,
Right, in this configuration, (troop with combat chinstrap), for the 1 GzF Regiment B II & III.
On the other hand:
---Officers have the fluted tip, unlike other Silver Guards or Eisenbahn regiments.
---The stars are silver, whereas they are gold on the others.
---The scales on the “officer” or parade troop chinstraps are silver, unlike those on other “silver” Guard regiments, which are gold.
In this “troop” confirguration, service or field dress, BII & III effectively, it's only the regimental stamp that can make the difference.

On the left, an enlisted helmet marked 1GzFR, the tip is higher, fancy, and the chinstrap scales are in maillechort (silver plated).
On the right, a Wehrmann helmet, marked E3 for Eisenbahn. (Landwehr).
brass (gold) scales.
Otherwise, the helmet is identical.