at renderotica there are a bunch of V4 gens and a modified V4 figure.
The one from RajDarge (Gspot) is mapped the same as the v4 hip so the v4 skin texture applies and there is a blend map supplied to merge the two textures fairly seamlessly.  DrTaj also has a postwork kit comprising a variaty of stuff as psd layers , with instructions on adding and blending them in .   
I am hopeless at postwork so Thats all I can suggest .