To Simon Jester and others who are interested in the whole show and weren't able to watch it because of Swedish television's stupid limits. Naturally, now it's available (in full) on YouTube:
In September SVT (Swedish TV) made a 45-minute special featuring the most popular artists in Sweden. The programme featured: ABBA, Lill Lindfors and Björn Skifs. ABBA performed 3 songs: Mamma Mia, I Do I Do I Do... and So Long. The show was presented on the MIDEM fair in Cannes in Janury 1976. (Thanks to www.myabbastory.dk).