I don't think you will find the lock and trim anywhere, except maybe the junkyard. They don't sell pieces to the rear sliding window, just the whole thing. I'm trying to make the lock from a chevy work on mine, it was free.
i dont know about their website, but thats where i got mine from was advance auto parts. i went and said "hey, i need this" and they hooked me up. now wasnt a ford part, it was universal, but it bolted right up and worked great.