[sharksfan2000]

Not that Wikipedia is always the most reliable source, but their entry on Fleetwood Mac includes an interesting late-'74 quote from Doug Graves:

After Warner Bros. made a record deal with the real Fleetwood Mac, the quartet released Heroes Are Hard to Find in September 1974. For the first time in its history, the band had only one guitarist. On the road, they added a second keyboardist. The first was Bobby Hunt, who had been in the band Head West with Bob Welch back in 1970, and the second was Doug Graves, who had been an engineer on Heroes Are Hard to Find. Neither proved to be a long-term addition to the line-up, although Graves was preparing to be a full member of the band following the US tour in late 1974. At the time he said:

I'm looking forward to adding something to this already great band; I helped engineer their album 'Heroes Are Hard to Find' and got to know each member well. It came to me as a shock when Mick asked me to join but I am enjoying playing live with the band, and hopefully will start a new studio album with the band soon.
—Doug Graves, Melody Maker 26 October 1974

However, Graves did not ultimately join full-time and Welch left soon after the tour ended (on December 2, 1974), having tired of the touring and legal struggles. Nevertheless, the tour enabled the Heroes album to reach a higher position on the American charts than any of the band's previous records.