Gentlemen, This is from the French reference book: Uniformes HS N°31:
1895 marks a revolution in the field of equipment of the German soldier. It has been 40 years that a reform of this magnitude had taken place. Equipment and uniform are modernised. A.K.O. of 25 May 1895 orders to modernise the Pickelhaube as well. In reality, it is mainly a confirmation of the 1891 principles and application of new fabrication techniques. The helmet dome is a bit lower and more cylindrical than the one of the 1887 and 1891 pattern. The Knopf 91 chinstrap sidepost will be preserved. A new fixation system for the Wappen is introduced: U-shaped metal brackets on the back of the Wappen replaced the bolt pins on the Mannsch helmets. In fact this system was already used in Bavaria since 1845. From then on the holes in the helmetshell-for lodging this U-shaped Brackets-are strengthened by metal eyelets. The rear spine for Fusstruppen and Train is equipped with a sliding air vent; a small hole is punched/drilled in the back of the helmetshell at the position of this sliding air vent. The base of the spike now has five ventilation holes.
-1895: The helmets of the Fusstruppen; only these-it seems-are then equipped with the rear spine with a sliding air vent-the so-called "Lüftungsschieber", with a small nipple for a better grip. It is an additional ventilation opening to the holes in the base of the helmets spike. This explains why the vast majority of helmets for the Feldartillerie features a rear spine Mod 1891 without the sliding air vent; while the Fussartillerie was equipped with the Mod 1895 type spine with the sliding air vent. Some Model 1915 Feldartillerie spines can be found without air vent. However: not all men of the FAR were mounted. These men would have to wear a helmet with sliding air vent…For sure: not an easy mission for the “Kammer”-the Battery Quarter Masters Store.
Certain helmets with the sliding vent wear the original “FAR” or “AR” markings in accordance with the regulations. Quite in contrast, however, 1903: Prussian Train units: mounted; will addopt the infantry helmet, with the rear spine...with the sliding air vent.
Francis