Well, That is true, at the start of the 69 build, they used the flatter "dished" metal and put the 68 "walnut" plastic on it. Then around Dec/Jan, they Chev put the matching "Rosewood" plastic on the flatter "dish" wheel.
It looks like the Walnut 69 wheel is now reproduced, but the color does not look like my original!
https://www.thepartsplaceinc.com/pro...d-ss-cap/88500