The complete "dome" is attached to the basic part of the center cap with a small screw, from the inside. Viewable after the three retaining captured-washer bolts are removed from the backside of the wheel.
Two styles of domes. The 1970-74 version had a taller dimension with outer splines on it. The 1975 C/B-body version was completely smooth, but used the same center cap base.
In 1974, the first B-body application was on the Road Runners with the "Radial Roadability Package" (Goodyear radial tires, with a rear sway bar added to the normal Road Runner calibration suspension).
The W23 Class II 16-Slot Chrome Road Wheels were all 15x6 wheels. Chrome was only on the slotted area, with argent silver paint from the chromed area to the wheel's lug nut area. With a trim ring covering the black paint on the outer part of the wheel.
The wheels were a nice upgrade on the 1976 Cordobas and C-body cars.
Just some observations and thoughts,
CBODY67