Henri,
Yes, any info is helpful. The Meiji period is a very narrow window, 1868-1912, but it could have been made outside of that period too.
The visor was loose when recieved. Would it hurt it's value, if it has any, to use a carding brush to clean it up? Carding brushes are very soft/fine SS use in the blueing process in gun restoration/making. I use the hand & or wheel version as needed for minor corrosion removal on my military collection as needed.
Everyone, please let me know your thoughts on a cleaning rather then a restoration.
Paul