1961 Austrian Postage Stamp - 75 Years of Sonnblick Observatory

This is a rectangular postage stamp from the Republic of Austria (Republik Österreich) issued in 1961 to commemorate the 75th anniversary of the Sonnblick Observatory. The stamp is printed in a monochromatic slate-blue ink on off-white paper with a vertical orientation. It features a finely detailed photogravure or copperplate engraving of the Hoher Sonnblick mountain peak, showing the observatory perched on the summit surrounded by snow-covered crags. The denomination 'S 1.80' (1.80 Austrian Schillings) is located in the top-left corner. Along the top, the text reads '75 JAHRE SONNBLICK OBSERVATORIUM'. Below the image, the artist's name 'H. RANZONI D. J.' is visible in fine print. Physically, the stamp features standard comb perforations (approx. 14 x 13.5) along all four edges. Regarding its condition, the stamp is in used (cancelled) condition, as evidenced by a partial black circular postmark on the bottom right corner showing fragments of the word 'WIEN' (Vienna). The serrated edges appear mostly intact with minor softening on the upper right corner. It is mounted inside a black protective stamp mount or 'hawid' strip, which is placed on a light-colored grid paper background for storage.