Looks like 16mm. snip off a bit so I can see the perforations on the side of the film. I can then tell you roughly how old. I can send the photos you posted to some retired projectionists that will be able to date the reel and the film, but you might want to do this yourself, I dont wanna spoil your fun. If you just look at one frame through a magnifying glass, you will see the make of the film in an instant.
Our National film archive restores stuff like this, they can work wonders as I am sure yours does. Id guess it is a TV reel, TV used to use 16mm. Less likely a real movie. Almost impossible to be a porno or a home movie, theres too much tape.
Im guessing it was stolen from somewhere and hadnt been where it was for very long. Kids probably.
It is not possible for an item such as that to remain in the open as shown in the pix for very long. It is in fair condition. Ive seen film stored in the original container deteriorate far more than yours that was out in the open.
Its looking like a hoax to me, as anyone would have held it up to the light by now, or at least noticed what is stamped on the reel.
