While i would date it from 1580-1600, i am ready to be corrected.
As i also dare to repute it as being authentic, with its 1247 grams weight, twelve brass rosettes and two holes in the back for the missing plume holder, a device not so often seen in this type. The armorers mark would identify it as Spanish ... well, apparently, when compared with Gyngells catalog and one similar example in the
LONDON ARMY MUSEUM.
Having said all the above, i would like so much to read your folks comments, including those revealing i am wrong.
Dimensions: Height 21 cms. Width 18X22 cms. with Brims 23X28 cms.
.