Between the dates you listed, there were 3 scheduled Led Zeppelin shows with others on the bill, however, Zep did eventually cancel their performance.
1. Mar 8, 1975 W. Palm Beach, FL - BTO and The Pretty Things were also on the bill. Show canceled due to local political issues.
2. Aug 23, 1975 Oakland, CA - Joe Walsh and The Pretty Things were also on the bill. Show canceled due to Plant's car accident.
3. Aug 24, 1975 Oakland, CA - Joe Walsh and The Pretty Things were also on the bill. Show canceled due to Plant's car accident.