Welcome and thanks for asking our advice.
The short answer: California considers all guns unsafe until proven otherwise.
As I understand it, every model and every configuration of gun has to be submitted to California for testing in order to be on the list of guns that California will allow its tender residents to possess.
If Ruger did not submit that particular configuration, California says you can't have it.
I was in a sporting goods store last year in Stockton when a customer walked in. He already has a gun. It was on the approved list. But then a clerk processing his supplication to be allowed to carry his gun noticed that there was a suffix (a "-c" or something like that) to the model number and turned him away.
Yeah, I feel for you and all residents of California and other oppressed peoples.
Lost Sheep