Hallo Erich,

die beiden Marken sind echt, die Signierungen ebenfalls.

Näheres zu den Signierungen kannst Du hier nachschauen: http://www.filatelia.fi/experts/namess.html

Stolow The brothers Henry (1901–71) and Julius, originally from Riga, were stamp dealers in Berlin 1920s to 1933, after which they moved to Brussels for a few years, before emigrating to the USA. In New York they (mainly Henry) were famous as stamp auctioneers and wholesale dealers. The company was also engaged in e.g. bogus overprinting on WW2 stamps [FFE7 p. 58], the 1945 Greenland overprints, Maluku Selatan phantoms and new issues for African republics. Some time after the war Henry returned to Germany. The Henry Stolow company's shop in Munich was still active in 2005. Gregory Stolow (USA) is son of Julius.

Nils Strandell was the foremost Swedish expert of his time.

Mit besten Grüßen
Siegfried