Well, since no onw else has made a response, I will venture that I do not live in Calif. and can not help you there. Do you do any welding. If so Lincoln has some project books, a Google search will bring up a lot of them, and there are 96 on ebay (of course about 90 are repeats of the same ads). I ordered one some time ago and it had a number of plans and designs for staircases including spiral ones in it.
Wish that I could be of more help.
Bill P.

I'm on the right coast, so can't help to much either.
But I have a link on my site for a fella in Anaheim, if that is near you.
Hope it is of some help.

Joe

Here is a link that might be useful: Jeff Rondini Welding &Handyman Services