Hi,
Here is a short You Tube item from Toy Tinker Tim on a toy movie viewer.
The viewer took various film cassettes, and was hand-cranked, as were many of these viewers.
The cassette shown is based on the movie Alien, and is called Alien Terror, copyright date 1979. It is a short reel of film highlights, without sound.
Clearly this was a toy aimed at younger children, yet Alien was R-rated in the USA, meaning that no one under 17 was admitted unless accompanied by an adult.
In Britain the film was rated X by the British Board of Film Censors - no one under 18 admitted at all, but now down to a 15 - no one under 15 allowed to view.
Most of these toy lines would have been in development and manufacture long before the film was submitted to the film censors, and rated, but it is hard to see R and X ratings helping to sell a toy line aimed at children.
There were plenty of other toys based on adult-rated films, or sometimes on a children's spin-off cartoon series. Very weird.