I am interested in how to make platinum-print-looking BW images with my digital darkroom.

Robert, if you mean in the chemical darkroom? The answer is sort of, but I'm not sure that is the point. I'm interested in how a frequency distiribution, in say LR, for platinum will differ from silver halide? For example when one uses different LR BW Presets you see the histogram changes. LR does not have a Platinum BW setting, for example. Maybe Topaz does and that is what I should investigate. It also may be that even if I understood what the histogram would look like, I would still have to worry as much about the printing process; e.g. papers, inks, soft proofing, etc.

Thanks everyone for your responses you are being quite helpful. Much appreciated. Bill P.