Original World War 1 German Steel Helmet in Relic condition repurposed in WW2

Original World War 1 German Steel Helmet shell in Relic condition appears repurposed An unusual find in that it has a small deliberately dilled hole in the crown and the remains of cream or white matt paint around the lugs, in small places on the rim and an irregular splodge of it inside, circled in the last picture. From what I have been able to discover, having survived WW1 it was put into storage in Germany and reused in a civil defence role, it may have been fitted with a different More comfortable?

Liner and for greater visibility during an allied air raid painted white/cream It is quite heavily rusted with some places where it is rusted through and the liner, whether original or added in civilian use is gone.

---