A file from my Pepakura making days that I discovered in Pepakura Designer you can export to .OBJ and in "Windows 10 3DBuilder or 123Design" export to .STL. Unfortunately I don't have the skills yet to improve further on the model, but maybe someone out there would like to tidy it up. Please upload it back as a remix if you do take the time to clean it up.
Please note this was originally uploaded to the net as a free down load. So I cant take credit for whom actually made the file.
A big thanks to dukekahedron for building the helmet. See pic attached looks great,cheers Jace