Robert C Kauffmann ( 1900 - 1999 ) was an American painter. Robert C Kauffmann s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 500 USD for A portrait of a man wearing a green necktie in 2005 to 1400 USD for A man showing a model of 'The Spirit of Saint Louis' in 2005 , based on the size and medium of the artwork.