Depending on the terminology the vendors use, it may be necessary to order a 24-pc body mount kit and a 4-pc radiator support kit to obtain all 28 items. In old Buick Master Parts books, the body was considered to start at the cowl and continue rearward to the end of the luggage compartment. Body mount positions were numbered 1 through 7 starting at the cowl. The mounts at the very front of the frame for the radiator support were called sheet metal mounts. See attached parts book page.
The Wildcat convertible uses one kit. The closed body cars use another kit. Here is a listing from Classic Buicks showing their BMK-342 kit for closed body cars:
Buy Buick Body Mount Parts front end mounts classic buicks vintage buick part antique buicks
classicbuicks.com
Here is a listing for Old Buick Parts radiator support mount kit CSK644 and individual mounts: