Layla is on a pignose?! Which part?!...And that Les Paul guy had a solid-state signature Gibson amp in the mid 1960's and used a Tech 21 amp throughout the late years of his career.
Then there were those little toy amps - like that "Deacy" amp Brian May made famous - and Pignose amps - used by guitarists such as Frank Zappa and Eric Clapton. You can hear that one on "Layla".