I'm not clear on the rules for linking to pornsites, but the site is "xhamster", and the movie is called "Undressed to Kill".

The porno sites XHAMSTER and XNXX are places where people upload all kinds of crazy shit. Not just video porn, but comics, cult horror movies, Andy Warhol Art films, nude performance art, music videos, documentaries. i may have encountered a John Waters film or two.

It took a long, long while for the kind of grainy, bad sound, no production values porn starring god-knows-who that I cut my teeth on to finally make it home video and the internet, and it probably never would have happened if not for the wonderful folks at Something Weird Video.

In case anyone cares, the best way to look for vintage full-length features is by year. Type in "1972" and see what happens. This stuff was legal to view, but illegal to make, and was shot guerrilla-style. In the words of Norman Mailer (or was it Gore Vidal?) it was the intersection of art and crime. That's a big part of what makes it fascinating.