Playing with some high resolution teactues (Ultimate Realism)for V3 yeaterday and applied to Millenium Pre Teen to see what would happen. To my surprise these textures applied perfectly, even the head textures. Nobody told me that V3 textures and Millenium kids were compatable! Or maybe there are some seam faults I couldn't see, but they looked perfect to me. Is this really the case?

Pretty much. You wouldn't notice the differences unless you did a close-up render and looked. A3 uses the same mapping as well. V2 maps work with the Mil Girls. Mil girls are V2 mesh, YT girls are V3 mesh. Check out UTC(Universal Texture Converter) at Daz, if you want to make the textures fit better for different figures. You don't really need to if your not doing close-up shots.