10 + 10 Pfennig airmail 1931, horizontal tete-beche combination from booklet pane sheet 10 on small piece, ideally central "FRANKFURT (MAIN) NORDOST 14 b 14.3.32 18-19", perfect condition, unsigned, H.-D. Schlegel BPP short opinion (2017) "faultless", outstanding item for highest demands without reservations, Mi. 400.-