10 C. Postal stamp ultramarine with overprint \"fortress Lorient\" as horizontal gutter pair with likewise overprinted blank field - variety \"stamp and blank field with inverted overprint\", printing machine number \"3\" on the gutter - in existing form probably the only one exists, slight defects like slightly thin perforation respectively left stamp with wood inclusion and brown spot, issued only 650 stamps - gutter pairs are only approximate 65 possible, but only a small part is as those have been preserved - extremely rare, certificate Herbst VP (2017), Michel - .