These are stills from a late 1960s hardcore stroke magazine called More Than Eight Inches. There was also a magazine of the era titled Eight Inches, so perhaps some competitive capitalism was involved.
Producing gay porn in the 1960s was still quite risky and could subject creators and sellers to criminal prosecution. Shoots went down on weekends in out-of-the-way seedy East Hollywood motels, and photos were developed in clandestine San Fernando Valley labs. The final product was churned out by cash-hungry San Gabriel Valley printers in the wee hours of the morning. I learned all this from a former neighbor who worked behind the scenes grinding out porn during that era.
If you'd like to see scans of the whole magazine, click here and download a free copy. I gamma-corrected some of the images that appear below, because porn print quality at that time was not the best.