stephen heller’s graphic timeline book may come up to the 60s.

you might want to take a look at the whole decade from a historic point of view as this country changed exponentially from about 1963 on.

you might contact house industries, they purchased the photo lettering library which developed through the sixties then exploded in the 70s (i think) so they might know some interesting stuff.

There’s a very short chapter in Lewis Blackwells’s 20th Century Type. Also, check out the Lettera series of books (more lettering, though).

And a quick Google brought up these links:
http://www.monotypeimaging.com/aboutus/MT1960_1970.aspx
http://www.agdproject.com/whenindex.htm

Veer has 50’s, 60’s, 70’s and 80’s timelines.

http://www.veer.com/products/type/