I have a name of someone who may be of some help regarding the Oland property in Carpentria, CA. His name is Stephan Bates, and is the son of the man who sold the property to the Olands in the 1930s. I believe that he lives in Carpenteria, but it may take some detective work to track him down.
Regarding the other property, that is another story, and I have been curious about that ranch in Mexico, as well.
Are you aware of Warner Oland's home on Pinehurst Road in Hollywood from the 1920s? The home no longer exists, but, the old address can still be seen near the street.