Found my dads original 1971 duster!
I haven't done a '71 dash removal. You can approach it a couple of ways. One is just remove the components - that's what I've done on my 67 with ralley panel. Other is remove the dash frame itself. I've not done that. Do look for ground wires. On the 67- there is one from the capacitor on the instrument panel to radio strut support (by the ash tray), another on the steering column to dash bolts, and a third from the heater (on top) to behind the right side passenger kick panel.