1945, fortress St. Nazaire, fieldpost letter with Standard stamp "b 3. 1. 45" with on the back senders note with fieldpost number "M 52361" ( = 10. mine sweeping flotilla M 428) and OKW-censorship "censor office e" to Berlin, stronger margin traces, for that complete with letter contents (dated St. Nazaire 2. 1. 45), rare