No, but before Led Zeppelin there were the Yardbirds. From the movie Blowup. Featuring Jeff Back and Jimmy Page:
http://www.youtube.com/watch?v=jSJGEn4FDys
This will knock your socks off. Check out Alan Price on the Keyboard. Part of the soundtrack of my life, indelibly etched in my cerebral cortex -
http://www.youtube.com/watch?v=P0-czS8PTBU
Its about three guitar players Jack White (White Stripes) The Edge (U-2) and Jimmy Page.
They do a lot of talking about their backgrounds and how they came about to be musicians but there is a point in the show where Page picks up his axe and starts to play the opening riffs from "Whole Lotta Love" and the reaction on the faces of the other two is priceless.
Page enthralls White and The Edge The sound on this version sucks but my High Def version is awesome to listen to.
All those guys, including Steve Marriot knew each other, but however much Jimmy Page might have enjoyed Marriot's voice, his existence was not integral to the formation of Zeppelin. Page looked carefully for his vocalist before he discovered Robert Plant.