Joe hasn't got a writing credit for
Rub Me Raw, although his guitar features heavily.
(Copied from Wikipedia)
"Rub Me Raw"
(Calderón, Zevon)
Warren Zevon – vocals
Jorge Calderón – electric guitar and bass guitar
Jim Keltner – drums
Joe Walsh – slide guitar
I checked ELP's,
L.A. Nights too. Lots of Walsh on it (vocals and guitars) but no writing credit.
There's a little more about Todd Rundgren's
Sleep on
http://927thedrive.net/news/classic-rock-news