Public Domain Movies released in 1973

Horror Express

In 1906, on a train racing through Siberia, Christopher Lee and Peter Cushing are engulfed in nightmare when a frozen missing link comes to life.

You can load the mpeg2 file into DVDAuthorGUI (a free program) and, with the push of a button, quickly create the structure of a DVD to watch on your television (after burning with ImgBurn or the like).

Invasion of the Bee girls

This one's about strange women who love their men to death, literally! Maybe the fact that there's a research facility doing top secret experiments might have something to do with the suspicious deaths.