The movie is wonderfully charming. It stars Tony Randall (in multiple roles) and Barbara Eden. It is based on a book: The Circus of Dr. Lao.
DVD Talk calls it "a minor masterpiece" and says, "Randall's makeup was crafted by William Tuttle who won a special Oscar for his work on the film." 1000 Misspent Hours isn't a fan, saying, "It isn’t an especially bad film, but this painfully corny family-oriented fantasy could still almost be used as a checklist of things that a movie can do to piss me off" although they do add this:
In its defense, 7 Faces of Dr. Lao is a very well made film. Its big selling point— the seven faces of the title— is an especially fine piece of work, even though it really amounts to little more than showing off on the part of the special effects crew. The acting is also reasonably good all around, despite the lack of any real standout performances.TCM has an overview. Rotten Tomatoes has a critics score of 100%.