69 Dart Rear onto a 73 Dart

Ok. Lets say i bought a 73, 74 dart. Easy to find and not good looking. What would it take to make The rear look like a 69 dart? Would it be to difficult to weld a 69 back half on? Anyone ever done it before? I know the Front clip, Doors, Dash all need changed to make it appear like a 69. But that is pretty simple.