Hi SalmanQ8,
The inner circle dial is definitely mother of pearl, though I am unsure about the piano keys. The uniformity of colour for the white keys suggests they might be enamel or some other material. The roman numerals are white gold, which look terrific.
I was a bit embarrassed about the quality of the photo of the display back, so I've atoned for my sin and provided a new one here for you and others! Looks pretty nice actually.
Displayback for AP Millenary PF