Bertram Dumbleton ( 1896 - 1966 ) was a South African painter. Bertram Dumbleton s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 49.08 USD for Stanislas Idzikowski as Blue Bird, signed 'Dumbleton' in 2005 to 1500.38 USD for A portrait of the artist's son, David Dumbleton, aged five in 2009 , based on the size and medium of the a