California requires that a handgun that is new or being sent to the state in a transfer must be on an approved list of "safe" handguns that have been through a specific test.
Most of these older handguns have not been through this test, even though practically identical versions are approved.
I don't believe it applies to moving into CA with a firearm and it doesn't apply to those owned in CA before the test was required.
I AM NOT an expert in CA firearms laws, not that anyone could be. This is my best guess from memory of reading things on the subject.