She is Sandra aka Monika aka Randy. Look here:
http://www.whichpornstar.co.uk/Sandra.htm
Whichpornstar list her even as Christine Scott, Silvia Cristian and Sylvia Rampling but those are aliases of Veronica Sinclair, who has a similar body, but is another girl:
http://www.whichpornstar.co.uk/Christine_Scott.htm
http://www.eurobabeindex.com/sbandoindex/silviacrist.html
http://www.egafd.com/actresses/details.php/id/s0112