You should be able to get any of the DeBeers advertising materials
from the Diamond Promotion Service, DeBeers marketing arm in the U.S.
Their web site is accessible to the trade only at www.dps.org. (If you
have a tradelock password through Polygon, this is the
access-restriction they use. If you are a member of the trade and
don’t have one, you can get one at www.polygon.net.)
You can also phone up their customer service center at 800-370-6789
to order materials, or if all else fails, call the New York
headquarters at 212-210-7590.
The consumer web site might also be able to help you: it’s at
DeBeers is normally very happy to share this type of material: a
friend was able to order a CD of the music written for those ads
several years ago. The ad you refer to is part of the aptly-named
Hope that helps!