Sealed beam headlamps

Hello, is there a way to legally drive or keep a US import with Sealed Beam headlights in Germany? Ggf with 07er registration plate? Or do they have to be converted to German headlights (or retrofitted is an Audi)?? And another question: Where do you get Sealed Beam lamps here? For you US specialists here a problem should be part of the daily bread, right?