As for the billet door handle tubs, there have been two sources to the best of my knowledge.
already referenced is the offering by Mark Johnson at IPSCO, but I do not think he is still selling them.
however they are still listed on his website so I would give him a call. Very nice man to deal with
another vendor who has offered them in billet, or at least he did, is Larry Stock in Carson City.
I have seen both of their offerings and when I bought my buckets, I purchased them from Mark Johnson.
Larry