1943, war navy, registered fieldpost letter to the marine artillery ordnance in Gotenhafen with mute postal stamp from 2.5.43 and fieldpost R-slip of paper with stamp overprint "Fp XIII" ( = navy field post office Gotenhafen 1) as well with service- and cover stamp army postal service no. M 36251 = command 27. U boat flotilla, good condition, Michel 250, 00