eurobabeforum.com

Gigi doesn't appear in this movie.
The girl that appeared as Gigi is Katarina Sydney.

The rest of the cast is here:

Katarina Sydney (as Gigi) [Facial]
http://www.eurobabeindex.com/sbandoindex/kat_sid.html

Cindy White
http://www.eurobabeindex.com/sbandoindex/cindyw.html

Lolly Blond (as Lolli Blond) [Facial]
http://www.eurobabeindex.com/sbandoindex/lolly.html

(Lulu and Sandra Black are correct)