http://www.ryland-cooder.com/
the last 8 albums listed on that site
were on the Warner label...
http://www.warnerbrosrecords.com/faq.php
perhaps you can locate
an agent or someone there
who manages him?
or here..
http://www.warnerbrosrecords.com/
UNITED STATES
Warner Music International
75 Rockefeller Plaza
New York, NY 10019
U.S.A.
or here:
http://www.repriserecords.com/

http://www.pbs.org/buenavista/music/ry_cooder_bio.html
http://www.pbs.org/buenavista/music/ry_cooder_disc.html
or on Warner Electra Atlantic's site:
http://www.wea.com/
info@weac.com
or warner music group
http://www.wmg.com/

good luck