Guitar Player, March 2003 page 50.

The article is about the Yardbirds. There is a picture of Jeff Beck and Eric Clapton, and isn't that Charlie Watts in the background ? Looks like him anyway. The picture is taken in 1983 at the A.R.M.S benefit in which "marked the first time all three Yardbirds guitarists shared a single stage." Anyway in the picture, Clapton is playing a MusicMan amplifier.