Belgian M31 helmet used by the Civil Defence

The following Belgian M31 helmet was used by the Belgian civil defense.
I found information from a real helmet expert. at:
http://casquescollection.skyrock.com/3038112889-763-BELGIQUE-Defense-Passive.html
 
See also: Belgian Beret Korps Burger Bescherming -Corps Protection Civil
 
Moto: Impavidum ferient ruinae = 
part of 'Si fractus illabatur orbis impavidum ferient ruinae' and means: 'Should the world break and fall about him, its ruins will strike him unafraid'.