I think I have seen people comment on this type of rim, but I have never seen a set in person. This listing is for parts listed about half way between San Francisco and Sacramento, California. http://sfbay.craigslist.org/eby/pts/2420131557.html
I have something similar on my '68 California GS. The outer portion of the wheel that is painted black should be covered by a trim ring. I have four with trim rings but no center caps and two really nice tires (and two that are worn but not all that bad) for sale. I'd sell them for $100 just to keep them in the family, so to speak. I just bought a nice set of 15 X 7 Rallyes and am itching to get 'em on my ride.