German WWII Multi-Signed First Day Covers limited edition of only 100 signed, signed by four who opposed squadron leader Bulloch during the battle of the Atlantic, featuring Karl Donitz (1891-1980), Erich Topp (1914-2005), Otto Kretschmer (1912-1998) and Reinhard Surhen (1916-1984) all signed in ink to front – with various prints of each