now, some old tyme advice
go out and buy a book called, ''instrument flying'' by taylor and read it...it will help you understand what you are going to be teaching and refresh you on what you should already be doing as an instrument rated pilot.
Also go to the US govt printing office and get the book on instrument flying from the FAA.
Of course you will need other materials, but do this right away and it is CHEAP AND QUICK...
after and I say again AFTER you have read these books a couple of times then go find an instructor who can teach you how to be a CFII. And yes , get the written done too.
I encourage you to find an instructor who was/is an FAA designated examiner or someone very, very experienced in instrument flying.
IF you do a good job just getting the CFII, and you have had a good instructor he may be able to send his overflow of students to you. Then repay the favor and use him for ''phase checks''.
Yes, you will have to study other things for the written, and I left out the AIM, but you should already have that now.
Use this as a really good time to consolidate your own instrument skills and teaching skills. You are old enough to get your ATP. That should be in the back of your mind as you are doing this.
I have a feeling if you went out to the Van nuys airport you might find what you are looking for. But get started witht those books.
Being a CFII (and hopefully soon an MEI) will broaden your own skills as a pilot and help you make contacts to expand your career.
I'd also have you read ''weather flying'' by buck soon too.
But california doesn't have weather does it? (kidding here...the worst Icing i've ever had was in Calif, worst fog, worst turbulence...out near truckee)
it will probably take you a good 20 hours of dual to be ready if you are fair to middlin'