Welcome to the Search and Reunion Message Boards!
That sounds like a good plan. Also, if you can view the marriage records they generally give a state of birth on the certificate.
California Search Website:
Other great websites to check out:
http://www.adoptionchat.com
http://www.adoptionlists.com
http://www.adoption.com
http://www.adopting.org
http://www.adoptionregistry.com