Frank/Nordstahl, you being in Germany, you have a unique opportunity with your car. When Ford was building Panteras for the USA, DeTomaso would pull a car or two off the Vignale assembly line as an unfinished shell, truck it to Modena and finish it according the laws in force for the country the customer lived in. He was licensed to sell Panteras to the whole rest of the World.
So after you get used to your new ride and if you feel up to the challenge, there are a number of Factory Illustrated Parts Manuals available on the POCA Web Site in California (free downloads for members). In them are listed specific parts used on Swedish, German and British Panteras as originally built. So you could maybe locate them and equip your car exactly as it would have been back in 1971 as delivered in Germany!
Some of the shops that worked with the Concessionaire for Germany (Armin Fischer down south near Stuttgardt, I believe) are still around. Things like seats, safety items, headlights, Blaupunkt or Becker AM/FM/shortwave radios and a few other unique parts- not a lot. Never heard of any other owner doing this but it might be fun for you. And you'll certainly learn a lot! Welcome!