The 'quote' you got was wrong. First, it is not part of the AWB. Second, you can not make or complete a firearm with the INTENT or for the PURPOSE of selling it. It doesn't say you can never sell it, just that you can't make it for the purpose of selling it. Making it with intent to sell is what makes you a manufacturer in the eyes of BATFE.
In any case, you have to deal with the requirements of Calif laws which only complicate the situation, if not prohibit the completion unless certain requirements are met (and probably approved) per the letter posted by Notack.