King Olaf by Kay Rasmus Nielsen that sold for £36,000 at Hartleys.
But the 17in x 10 1/2in (43 x 27cm) illustration was in fact an original and it was passed down by descent to a local woman who entered it into Hartleys' September 9-10 sale in Ilkley, West Yorkshire.
The work was in very good condition, inscribed and dated 1913 and bore an exhibition label verso for The Leicester Galleries, London.
Estimated cautiously at £1500-2500, it sold to an American buyer for £36,000 plus 15 per cent buyer's premium.
