The album cover for Led Zeppelin II was from a poster by David Juniper, who was simply told by the band to come up with an idea that was “interesting.”
His design was based on this photograph of a Division of the German Air Force during World War I. Dubbed “The Flying Circus” and led by Manfred von Richthfen “The Red Baron.”
He airbrushed the photo adding the faces of Jimmy Page, Robert Plant, John Paul Jones and John Bonham taken from this 1969 Led Zeppelin publicity band photo.
He also added the faces of manager Peter Grant and tour manager Richard Cole.
The woman on the album cover is actress Glynis John (the monther of Mary Poppins). Her presence of photo was a play on the name of recording engineer Glyn Johns.
When Juniper himself, was asked about the other people featured on the album cover he said,
All the faces were replaced or altered (sunglasses & beards on some of the pilots!). In amongst the four band members (airbrushed in from a publicity photograph) are Miles Davis (or was it Blind Willie Johnson?), a girlfriend/muse of Andy Warhol (perhaps Mary Woronov) and the astronaut Neil Armstrong.
Juniper thought he had put Neil Armstrong on the cover but actually put NASA Astronaut Frank Borman on the cover by mistake.
Wikipedia is wrong. A look on Google images will show that there is plenty of photographs of Blind Willie Johnson. That false information about there being only one photo first appeared on wikipedia, and is not cited.