I'd like to have an answer to that question too.
I have a pair of 14 inch all chrome D caps in my storage. The tabs ren continuously around the circumference of the cap. The backside has a shadow chrome number of "1036" on the backside. One was loose in the back of my 10/1970 series one. The other was on the spare tire wheel [4.5 inch wide].
The centers show no sign of ever having been painted. Over the year, I've located only one photograph of this style and I didn't place mark it. Any one know anything about these caps. Aftermarket? Datsun?
g