Danish helmets of the Cold War
The Danish army used a variety of helmets during the early years after the end of the Second World War. The Danish Brigade in Sweden (DANFORCE) had used the Swedish M/37 helmet, and that particular model saw a little use in the Danish army in the years immediately after the war. As a part of the occupational forces in the British sector, the Danish Brigade in Germany was equipped like any other British infantry unit - complete with Mk II helmets (and the occasional MkIII helmet).
To replace the amount of MkII, MkIII and M/37 helmets, the Danish army tried, but failed, to make a home grown helmet, that was sufficiently cheap and offered good protection. The M/46 helmet was a failure. Not that it wasn't a good helmet, but the surplus market was ripe with good cheap helmets, and the Danish Army chose the US M1 helmet instead of making their own. The US M1 helmet and German-Austrian clones, served in the Danish army until the 1990s, where they were finally replaced by kevlar and composite helmets.