eng92cap

Hello to all! My first day here. I want to make a replica of WW II USN cloth flying helmet.(Headpiece worn by fliers in Pacific air battles). Pilot had leather cups sewn to cap (helmet) over their ears to hold radio speakers. See picture at link below. Can anyone tell me what weight of leather to use? What type of leather? Best way to make a mold to form wet leather? Many thanks for you help, respectfully, eng92cap.