Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

I can't ID the broad italic sans used for this issue. Akzidenz Grotesk and Standard are close, but the beardless 'G' is a puzzler. It rings of Venus and Ideal Grotesk, but no match.

mid-century modern design in America: Clarendon (for the logo and issue numbers), Century Expanded, and News Gothic.

Massimo Vignelli took over as art director in 1968.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

Source: http://www.flickr.com.Images via Sandi Vincent on Flickr. License: All Rights Reserved.

December 1956 cover designed by George Nelson? (This image via Laura Berner.)