Saw this recently over at Design Observer and was struck by, in the words of one of the commenters, its simple, understated design. The typeface is Helvetica Standard Medium.
-
-
Submitted For Your Perusal is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
-
Submitted For Your Perusal 
I was Paul Rand’s assistant at the time this letterhead was done circa 1964. Helvetica wasn’t available in the United States at that time. We used Standard Medium in lieu of Helvetica.
Jayme Odgers