From research, I believe this is a Gentexite H3 fighter pilot helmet from Korean War era. I acquired it with a Gentex Mil H7151 headset liner and extra Roanwell mouth piece and keeping together. Helmet rather nice used, vintage condition. There are the names Bunderson and Biggs written inside the helmet which I did find both these names serving in the Korean War. Whether either names are relevant with helmet is underdetermined.
Liner in very nice condition. Please see pictures and feel free to ask questions and I will do my best to answer. The item "Vintage Gentexite Gentex H3 Fighter Pilot Helmet W Liner Headset Korean War Lot" is in sale since Wednesday, February 21, 2018. This item is in the category "Collectibles\Militaria\Korea (1950-53)\Original Period Items". The seller is "ajoyp81" and is located in Omaha, Ne.This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Russian federation, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Chile, Colombia, Costa rica, Panama, Trinidad and tobago, Guatemala, Honduras, Jamaica.