I see the differences in the color and I believe the steel portion is the same (stamping number verifies this)

But due to different part numbers on the 68/69 = 4016DTT wheel compared to the 1970 wheel 4016FTT ??????
Leads me to believe the difference is in the color OR maybe the filler ring was attached OR maybe the steel portion was modified to accept the adapter, hence the different part number.

But, In the upper level show circles it's the general accepted rule the 1970 wheel is darker.