Interesting article about the Kalkriese mask!

[Peroni]

If anyone checks out the Kalkriese mask they will find that there is a gap at the centre top of some 4to5mm, also there are two small holes that did indeed hold the edge strip in place infact one still has its rivet there with a small bracket.

I believe that these two holes (below the gap) is is where the hinge was attached as seen on similar masks.(for example the helmet from the Levy / White collection)

I don't know who did the drawing, but it comes from one of the Birley publications - possibly 'Garrison life at Vindolanda' a band of brothers.