Izzy has a writing credit on Locomotive according to ASCAP, a song he didn't write a note of and didn't even perform on
Slash and Izzy wrote the music to Locomotive when they were living together in the house in the Hollywood Hills in early '89.
The credits on the album sleeves are not the official ASCAP credits, for example on AFD the band worked out a percentage scheme for every band member, including Steven Adler, who obviously never wrote anything for GNR. Every GNR song is officially credited for a different percentage to each member of the band (for UYI minus Steven Adler).