This is a very interesting model I have not seen before, are there any makers details provided?
Your theory of being a miners helmet makes sense, therefore could be made by MSA, but the cage face guard could indicate riot usage?
I hope someone else here can shed more specific information on it's provenance, and I must say I would be keen to own it as it has the type of features with direct links to the M1 designed liners, overall a fascinating piece well worth researching and ultimately owning.
Interesting thing. My first impressions were that it was certainly post-1940s, as per the Riddel-type liner and headband, and very likely Japanese, as per the cloth chinstrap rig. And definately likely a riot helmet as a faceshield like that would be useless to miners. Though a sports protective helmet of some kind wasn't off the table.
Anyway, a few minutes checking on the usual subjects on the web gave me nothing, but then I look a look at Marzetti's ELMETTI, but still no joy under Japan (or Giappone is you wish to be precise). But thinking back a few decades or so the most likely place for full-on rioting in Asia was usually South Korea - and here we are then, page 90 of the 3rd edition, picture 20.8 - "Military Police riot helmet made in South Korea and exported to Asian countries, one of which was Malaysia" There's no date attached but because of its placing in the country entry I would believe it to be 1960s-70sd at the latest. There's actually no entry for Malaysia so cross-checking was a bit of a dead end. There's only one picture, of the exterior from the front-left side (and it has a lobster-tail neckshield attached - see probable fitting points on the rear of the example here), but I'd bet a decent amount of money this is your man.
Great detective work Greg, certainly looks the same model
the shape kind of resembles a Japanese M30 steel helmet? I agree it does look like something used in post war Japan as a Police riot helmet and the because of the type of chin strap used.