There are plenty of non water mark pictures in both of these. I don't know if any of them you like, there is certainly a lot between them.
http://forums.ledzeppelin.com/index.php?/topic/11210-cool-pics-of-jimmy/
Not so much Zeppelin history, but today was Scarlet Page's birthday. March 24, 1971.
And Today through I think Saturday, (3/24-3/27) they played the Forum in LA in 1975.