That’s “Visco” as in The Visual Index of SF Cover Art. It’s a wonky site, but potentially a great resource, especially if they come anywhere near their goal of putting up a cover image of every science fiction, fantasy, weird and horror magazine ever published in the English language.They already have a substantial collection. Have a look. If you don’t know where to start, you might try Mel Hunter’s “Last Robot” series, published as F&SF covers between 1955 (that first one was a little clunky) and 1971:
Gardening, Oct. 1955 :: Phonebook, July 1957 :: Yoo-hoo!, Dec. 1959 :: Audiophile, May 1960 :: Wind-ups, Dec. 1960 :: Art museum, Aug. 1961 :: Santa Claus, Jan. 1962 :: Landscape, March 1964 :: Hotrod, Jan. 1970 :: Bookshelf, May 1970 :: Traffic light, Sept. 1970 :: Rowboat, Dec. 1970 :: Vanity, March 1971 :: Baseball, Oct. 1971 :: Punch & Judy, Dec. 1971.I love those covers. Somebody ought to reissue them as prints.