Fujitsu is pretty tight lipped about the inner workings of their tablets. I could only suggest a few avenues to pursue. TabletPCBuzz.com forums may have some folks that have some experience in this area but they are extremely slow to respond to newbies. TurboCad6 has the most experience on this board dismantling newer Fujitsu tablets. Or you could dismantle it and send as much info on the individual parts to MotorCity on this board and he may be able to help you. MotorCity may, for a reasonable fee, be able to create what you want if you send it to him.
Unfortunately, your purchase of the 4121 may have been premature. I'm sure for the time and effort you're about to expend for this conversion, you probably could get a decent transflexive screen. OBTW, you can send me the guts you don't use when you're done.