The photo above shows a 'some teeth missing' Prince Far I, I found this photo on the internet (I think it was displayed on the Efa Medien site which now seems closed).

According to Stephan Goffings the Picture was shot the second of march 1981 during the Show at Bonn Rheinterassen. It was carnival at this day (in Germany it's called "Rosenmontag"). The Picture was originally for the first time released in a German Music Magazin called Spex. It also includes a review of the show, written by Walter Dahn.