1970-03-07 Montreux Information
Recent research, most notably in the book "Led Zeppelin - The Montreux Concerts"published in 2001 by Gilles Chateau & Sam Rapallo (led-zeppelin.com), clears the historical confusion regarding this performance.

"Contrary to popular belief, Led Zeppelin never participated in the Montreux Jazz Festival (on 1970-03-14). During initial research in the early 90's, the correct date of their first Montreux concert (Casino Royal, Montreaux) was confirmed as March 7th, not the 14th as previously believed. A concert scheduled in Geneva on the 7th was replaced with the Montreux show."

Lewis & Pallett have the dates correct, Luis Rey does not. Maybe in his next edition (we hope!). Thanks Roland for providing this information.

Cross References:
1969-03-19 Sunshine Woman (Flagge)
1970-07-12 Intimate Almost Mysterious (Equinox)
Compilations Complete Tapes Vol 2 (Tintagel)