Welcome to the forum Sean
. The white panels are "dielectric" panels i.e. antennae for radios. You'll see the early IIICZs had no blade antennae. These were introduced later as equipment upgrades came about. If you're modelling an early CZ without the blade antennae, then you'll need to paint them on. Regarding the silver nose section, your guess is as good as mine. Post images of your Mirage please
Note also that these panels had a dark grey leading edge. There was also a rectangular white dorsal antenna just aft of the canopy.