From the listing:
For the 1966 season Jack Brabham teamed up with Australian company Repco to produce engines for the new 3 litre Grand Prix regulations. The team had an incredibly successful season starting with the 1965 BT19 modified to use the 3 litre V8 and when ready the purpose built BT20. Chassis 1 was used by Brabham towards the end of the season and consolidated his third World Driver’s Championship, the first for a driver racing a car bearing his own name.
As with the BT19 in ’66, the BT20 started the ‘67 Grand Prix season before being replaced by the BT24. Brabham raced BT20/F1-1-66 in the South African GP, the Race of Champions and the International Trophy and won the Spring Trophy at Oulton Park before selling the car to South African operation Team Gunston. Gunston ran the car for three years, usually with John Love driving for the team.
In 1971 famous Brabham exponent Charles Vogele bought the car back to Europe and then sold it to Tom Wheatcroft for his ever expanding Grand Prix Collection. The BT20 remained at Donington until 2010 when the current owner purchased the car. BT20/F1-1-66 is the only BT20 currently racing, the other residing in a museum in France.
Currently listed at http://www.taylorandcrawley.com/current-stock/Race-Cars/Brabham-BT20