Hello gentlemen,
time ago I have purchased this pickelhaube.I believe it is pure pattern M.1871 for OR.
On the rear visor is marked : 4GGRK / 4.Garde Grenadier Regiment Koenigin/ 1889, 1B,1C and 1889 again.
As known-since 1889 -by all 5 Grenadiers Regiments-was the Grenadier´s Eagle replaced...