I haven't spoken with Dick in some months, but it is my understanding
that the Crane's Platinotype paper he uses is the current product. He
uses quite a lot of it too.
Perhaps you are thinking about the change from Crane's Artifical
Parchment to Platinotype. Artificial Parchment was what Dick was using
(and is no longer available, I believe) before he got Crane's to make
Platinotype.
As for the subtle brown tones, I would bet that most of that is in the
negative. Dick just takes a good snap. The color can be varied with
chemistry. I would suggest trying a straight palladium print.
David