None of the tracks on Drat That Fratle Rat used the complete band of the time, but instead
used selected members, augmented by guests -- mostly well-known musicians on the Rock scene.
See the scan of the back cover, above, for exact details.
It's also worth noting that three of the tunes were co-composed, and all but one produced, by
who joined the band in 1971, replacing Stu Morrison on banjo.