The picture as oiginally shown in HRR's work is somewhat different. The piece now seems to be displayed with a face mask.
The distinguishing feature seems to be the transversally ridged brow plate embossed with projecting laurel and oak leaves and a central human bust.
The left side carries a plume tube that may have had a companion on the right.
A surviving cheek piece is faced on the iron with a thin bronze sheet embossed with a mounted Dioscurus within a 'pearled' frame. A simulated 'ear' is embossed in the upper rear corner.
At the centre of the occiput is an applied bronze boss, embossed to represent a rose-like flower.
References:
Robinson, H.R. (1975), "The Armour of Imperial Rome", (Arms & Armour Press), p.98, No.269-71
Klumbach, H., (1974), "Römische Helme aus Niedergermanien", (Bonn), p.46 & Taf.33
;)
;)
;)
;)
;)
;)