German East Africa Sc #11-21 (1900) 2p to 3r Kaiser’s Yacht Set Used on Piece w/Certs

2p brown to 3r dark red and greenish black, depicting the Kaiser's Yacht "Hohenzollern", each exampled tied to piece by neatly-struck c.d.s., most Dar Es Salaam, noting also 2p and 40p Kilwa, 5p Langenburg, and 10p and 15p Muhesa, chiefly fresh colours and well-centered, the 10p with small tone spot at upper left, a lovely and scarce group; with Steuer certificate for the set, Jaschke-Lantelme certificates for 19, 20, and 21b. (Michel 11-21b).