Standard production stainless steel Deluxe Wheel Cover, GM part no 9700839
This one is similar to the Deluxe Wheel Cover used on other '63 full-size Buicks.
Optional cast aluminum Super Deluxe Wheel Cover with spinner, no 1359946
This one could be called a cast-spoke design. A similar cast aluminum cover was used on the ‘64 Riviera.
Optional Wire Wheel Cover with spinner, no 1358215
This cover was also used on many other full-size '63-66 Buicks.
Here are the pictures in a message thread from AACA: