ref: Zito 1970: "The Caravan of Love tour is heading east en route to an Aug. 25 appearance at the Isle of Wight Music Festival".
ref: Scott et al. 1995, xii
This tour did in fact happen, and was filmed for the movie, but the GD backed out at the last minute. Alembic however was still under contract to do sound, so mixers Bob Matthews and Betty Cantor and the sound crew went off with the Caravan.