Well the default 47D40 (a bare metal plane) has:
0.400,0.400,0.400,Ambient
0.600,0.600,0.600,Diffuse
0.000,0.000,0.000,Emissive
0.000,0.000,0.000,Specular
0.000,Power
Whereas the default 47D25 (a painted plane) has:
0.361,0.361,0.361,Ambient
0.400,0.400,0.400,Diffuse
0.000,0.000,0.000,Emissive
0.122,0.122,0.122,Specular
15.000,Power
I'm using the top at the moment. I might just steal the P38 materials file.