Yes, know this car personaly from it staying in the Rosss Bianco collection. Had been in touch with Muellers son Daniel and Robert de la Rive Box, who was the swiss dealer who sold it to Ron.
Actually when the Rosso Bianco collection was dissolved upon closing of the museum in Aschaffenburg, I asked if Ron had gotten those news. He had not even been notified yet by the R.B. museum (probably since Ron had returned to the US in the meantime), so he was happy to hear the news and claimed ownership immediately with the agents, before the collection got mostly sold to a museum in the Netherland and several cars being auctioned off.
Here is a pic of its first appearance at the Ring after the restoration out of R.de la Rive Box book.