This Convertible D advertisement is from Sports Car Illustrated, May 1959 (pg.75), and also ran in Road & Track in 1959. The advertiser is Hoffman-Porsche Car Corporation of New York. Note how the ad seems to de-emphasize the car in favor of images promoting the Porsche "lifestyle": sportsman's cap, scarf, and pipe! [Reverse side of magazine page showing a different car ad]
Below is a 1958 magazine ad showing a Convertible D with twin decklid grilles. This is probably 85502, the second prototype D. It was purportedly used briefly by Ferry Porsche, and customized with twin grilles and "Speedster" scripts. There is no evidence that any other D had those two features installed at the factory. Built for export to the USA (note the overriders), the car was shipped to San Bernadino, California. Current whereabouts are unknown.