The problem with using parts from an already constructed cab is that they aren't all that easy to get out undamaged. A lot of the spot welds are tough to get at with a spot weld cutter (hollow drill), and some spot welds go thru three thicknesses of metal. Even when I didn't care about one or two of the original parts I was removing, it was still a challenge to leave the one I was keeping intact. Even though most of the repop parts need to be massaged to fit, especially in the cowl area, it will probably be best to use new metal in some instances.
Hope your wizard is up to the task.
Here's a shot of my cab when I got it.
