Finally...
Process is as follows for me..
Create Skin. Save as PSD file in CS2. Open in Gimp 2.6, merge visible layers, save as bmp at 32 bit RGB.
Create Bump Map. Save as PSD file in CS2. Open in Gimp 2.6, merge visible layers, save as bmp at 32 bit greyscale.
In CS2 open up bump map file created above and saved as 32 bit RGB. Utilize Nvidia Normal plug-in to generate Normal Map. Save file as bmp.
In Gimp 2.6, open Normal map file. Save as bmp at 32 bit RGB.
Rinse and repeat for greyscale 8 bit _E, _P and _S files.
Also note that the files are named, P51D.bmp , P51D_N.bmp, etc etc.. not P-51D.bmp... (DO NOT ASK)