In a guardroom in the Castel Sant’Angelo preserved as an example of what such a space would have looked like in the 17th or 18th century, a row of steel helmets have been laid out:
Swiss Guard Helmets, Castel Sant’Angelo
In a guardroom in the Castel Sant’Angelo preserved as an example of what such a space would have looked like in the 17th or 18th century, a row of steel helmets have been laid out:
dcphotoartist 
So cool!