The modifications for this are extreme. It's really wasn't that easy to figure out. The parts needed to make the seats slide up and out required a lot of alterations, and customs parts (not to mention blood, sweat, and lots of swearing).
Let's just wait for Graham to give me a response as to wether Yamato wants to do this or not.
The design for the transformation mechanisms on this VF-1D are actually the forefront for the VE-1 and VT-1, but not exactly the same as the VF-1D. You'll see it in due time.