Good point here. It has to be "as built" but there's a loophole that allows a mod if the original parts are no longer made by the factory or available in the aftermarket. This car is nearly 30 years old and may, due to its age, well off the radar.
Originally, Calif. exempted anything over 25 years old. In the early
1990s the regulations switched to include everything back to 1967. That was the point I gave up on trying to skirt the law and switched to the 'vette. It might be a good time to see if there are still factory parts to "restore" it to, "as built" If not, and the aftermarket can't duplicate the whole system then a "best effort" to make the car comply might be in order.pj