These shots are from a smut magazine with the rather silly title of Phallic Phacts. I'm guessing it's from the early 1970s, based on some of their clothes and other clues seen in the pictures. The magazine is something of a ruse, with a quasi-scholarly discussion about penises used as editorial content to wrap around hardcore, explicit shots of men fucking and sucking.
I like the look of many of the lads in this publication. They don't seem like zoned-out druggie hustlers, what you often see in old porn. Some of them are also quite nicely endowed, too.
The last shot illustrates a technique many lads have figured out on their own quite early, include yours truly. When your cock head is slick with precum, you gently roll the palm of your hand over the surface. It's great to do to a friend, too.
If you'd like to download a free folder containing scans of the entire magazine, be sure to click here (mirrors here).