I believe this helmet is a M42 German helmet. I can only remember back to the early 1950s when these two German helmets were in my father's possession.
Unfortunately I never learned how he acquired these two helmets. This German helmet has the number 2157 stamped on the back of the inside. The number above the 2157 is EF66.
I do not see damage to the helmet other than normal usage. Feel free to ask questions. The item "WWII M42 German Helmet GerHelmet2 Shell Size 66 World War 2" is in sale since Thursday, May 26, 2016.This item is in the category "Collectibles\Militaria\WW II (1939-45)\Original Period Items\Germany\Hats & Helmets". The seller is "peter12601" and is located in Poughkeepsie, New York. This item can be shipped worldwide.