Italian Model 933 helmet
This ia a pre WW2 helmet.
My helmet is in a beautiful condition and has a leather chin strap
The picture above shows the inscriptions in this helmet.
I don't know what the FM means, the 56 could be the size.
There is also a number in the front, at the inside 253 followed by a little anchor.
This little anchor tells us this helmet was ment for use by Regia Marina, the Italian Royal Navy.
More information about this helmet can be found at my favorit web site:
I also found this Italian web site:
This is a webside of the Italian Army: