I'm thinking the PCRBA is the club I don't know exactly what it stands for: Pretty Cute Rabbit Breeders Association? and then the SB or SA would stand for Show B or Show A.
I know your are in California but is it possible that this rabbit was bred in Missouri? or around there? - I just ask because I know there's a club in Missouri called Phelps County Rabbit Breeders Association. I keep thinking that when I see the Initials