M33 helmet - need pointers to i.d. a WW2 correct shell/liner

[saddler]

Hi

Not found a great deal on the web about the M33 helmet.

I see all original war-time examples for silly (expensive) money - then "M33 type" for silly (cheap) money.

Aside from the issue of the liners being upgraded post-war, etc. are the main steel shells basically unchanged?
Are the "type" shells correct to use for a WW2 impression/restoration?
I want to make up a WW2 Finnish contract M33 helmet, so as long as I can find a donor shell I can make up a Finnish or standard WW2 era liner/chinstrap.

Aside from the shell itself - what information is out there for the RAL codes of paint that would have been commonly used in circa 1940.
(The Finns were not keen on the donated M33 helmets or the Carcano carbines & they both soon saw relegation to reserve units & training roles)