Histograms in LR or PS for BW platinum prints

This might help:

http://www.luminous-landscape.com/tutorials/platinum.shtml

In particular, this quote from the above link:

"The natural response curve of the chemistry is very contrasty in the mid tones and very flat in the shadows and highlights"

And if you Google "platinum print histogram" this shows up at the top of the list.
http://artofplatinum.wordpress.com/tag/tom-baril/