The most famous quarrel over a car, was between two Ferrari owners, because they each had a copy of Ferrari 330P chassis # 0818

The Italian court affirmed in 2011 that the only real 0818 was that of Italian Fabrizio Violati. A characteristic case of a car whose pieces were used to rebuild two cars

http://www.aonclassiccar.fr/2016/07/voitures-de-collection-fausses-et-usages-de-fausses/

after being raced by Graham Hill, at Sebring, Le Mans, etc, here is it's history
1966 - chassis stayed in a garage that David Piper shared with Tom Meade in Modena.
77 - Mike Oustromoff, Redditch, UK
77 - restoration started using the original engine and chassis, new body built by Wakefields of Byfleet, UK
81 Donington
81 Monthlery
82 - Christopher Murray, Middletown, RI, USA (drug smuggler)
82/sep/04 20th anniversary 250 GTO Chris Murray/ Francois Sicard "58 D 1799"

84/dec/17 - confiscated by the US Government and offered for sale
85/jun - offered for $250,000.
85/oct/30 - Fabrizio Violati -  through US Government and court of Bridgeport/CT
86 - nose redone by Allegretti, Modena, I
89/aug OGP Nuerburgring Stefano Durelli
89 - Fabrizio Violati "Maranello Rosso", San Marino C178 p32
2006 - Cerificate of Authenticity issued by Ferrari Classiche, no. 037F

http://www.barchetta.cc/english/All.Ferraris/Detail/0818.275P.htm

Dick Protheroe,  British gentleman racer, had the car re-bodied to P2 style by Drogo, but then he crashed fatally with the car.

The remains were eventually acquired by Mike Oustromoff, who used the original engine and chassis for a reconstruction. After a brief spell in the United States, the car was bought by Fabrizio Violati in 1985 for his Maranello Rosso museum.
http://www.ultimatecarpage.com/chassis/784/Ferrari-330-P-0818.html