I don't want to burst your bubble, but most all the black plates were used up with the 1968 model year cars. All the 69's seem to have the Blue and Gold plates.
You might just have a Hollywood prop license plate.
Maybe so, bit it's got the 69/70 CA registration stickers on either corner, is verified as having come with the car when it sold in 70, and matches the plate in the shots from the show. I'll need to look at it again to verify the color scheme.