I got my Dirt Bike in the mail today, and low and behold it has an article on this very conversion. It confirms that they used 250F parts, that the subframe has to be moved out at the top, and that the tank was not modified. I am going to try to fit my parts to my 2005 KX 125 to see if that makes any difference in tank fitment, otherwise I am going to heat mine.
Here are some new pictures they didn't show in the e-mail. They did there top subframe spacing bracket exactly how I was going to do mine. It's nice to know I'm on the right track.