IMO it's pretty darned pixellated. Only thing you can really see is blurry teeth.
It would go on the G model.
If you don't know how to edit the materials file, the best easiest first step is to find a default skin similar to what you want, and copy that value over. Say there's a nice OD plane like (hint) the B-25C. So right click on the B-25, save default skin, go find that directory, and copy this materials.txt over to your P-38 skin's directory.
However you'll find certain areas of the P-38s are hard coded, like the anti-glare. The materials file won't account for discoloration in these areas.