https://www.ln-online.de/Lokales/Luebeck/OCC-Kuestentrophy-in-Luebeck-120-Old-und-Youngtimer-am-Start
According to the article: Der Erstbesitzer sei der berühmte deutsche Verleger und Publizist Henri Nannen gewesen. „Und es sollen in diesem Auto schon berühmte Persönlichkeiten wie Gorbatschow, Schmidt, Mitterrand und Kissinger gesessen haben“.
which translates to:
The first owner was the famous German publisher and publicist Henri Nannen. "And famous personalities like Gorbachev, Schmidt, Mitterrand and Kissinger are said to have sat in this car,"
I have to admit, I didn't know who Henri Nannen was, so hereby the Wiki article: