German New Guinea 1897 3-50pf Set Registered Bahnpost Cover Matupi to Frankfurt

Cover franked with set of six (3pf to 50pf) 1897 issues of Germany overprinted “Deutsch-Neu Guinea” diagonally in black, tied by Matupi c.d.s. (28 Apr), registered to Frankfurt, with dual manuscript “R762 / Matupi” registration mark in red and “Vom Ausland / uber Bhnpost Nr 19” etiquette, with c.d.s. arrival backstamp, a rare usage with tremendous visual appeal; signed Bothe BPP.