Faraam Knight Helmet - Costume Helmet for 3d Printing

I'm a reasonably competent CAD modeller who has taken up costuming as a hobby on the side. Sadly my organic/soft 3d modeling skills are lacking so I'm looking for someone to help me with this project: The objective is model the Faraam Knight Helmet from the game Dark Souls II. The deliverable is digital file (STL or OBJ) that is suitable for 3d-printing. Object must be a "watertight" mesh with all the surface normals aligned appropriately. No textures or surface maps required. The printed object is intended to worn as a costume piece, so the interior of the helmet should be hollow to fit a human head. The in-game model is sadly too low-quality to use as a good reference, but a reference package of images taken of an official statue will be provided. If you have questions, please ask away. If the project goes as hoped, it may lead to a further separate commission for the remaining hard armor pieces (shoulder/chest/etc).