Perhaps I missed it, but after searching the forum of relevant threads on this problem, I couldn't find any.
Seems that whenever I attempt to apply any additional provided content textures to the basic MAT, such as the Bonelord or one of the facial beards, the face turns white and renders with the original MAT texture. When I check the material room to make sure the proper tex has loaded, it hasn't. I stlii get the original. Applying the MAT file by hand after browsing for it doesn't help. The proper file now appears in the preview window, but still renders to the original. or very rarely,null white. The correct Apollo jpeg's are in the proper folders.
I feel like an idiot. Anyone else had this problem?
( In my opinion, Apollo is far and away the best male figure avaiable in Poser, or in any other 3D program for that matter. )

The bonelord mask and the scalp/ beard are separate figures that need to be applied to apollo first. Then use the tex on them.

I have done, and the results are the same. Every permutaion of texture application I have tried so far fails. whether I apply the P4 base tex first ot the other way round.