Antique military?/ceremonial?/decorative chainmail helmet

Hello and thanks for any assistance you can provide.  I know nothing about this helmet.  It looks old and is quite rusted but I'm not sure of it's age.  It also looks hand tooled and etched but again I'm uncertain.  I can't find a country of origin or maker listed anywhere.  I would greatly appreciate any info on this helmet and whether or not it has value.

Thank you ,

Justin