However, Richard Thomson of the International Art Centre said the latest version was probably the first or second of the five or six versions Moore-Jones did of the painting, known as Simpson and his Donkey.
It is signed and dated 1915.
Moore-Jones died a hero in 1922 after he was badly burnt rescuing people from a hotel fire in Hamilton.
He never learned that his painting, which he originally named after John Simpson Kirkpatrick, an Englishman who enlisted in the Australian Army, actually portrayed the Kiwi, Henderson.
The painting is owned by the Commerce Club of Auckland, formerly the Commercial Travellers Club, which bought it from Moore-Jones' widow in 1926 for 300 pounds.
It hung in the club's Remuera clubrooms for many years before it was loaned to the Auckland War Memorial and Museum where it has been an integral part of the Scars on the Heart exhibition.
The exhibition covers New Zealand's involvement in wars, from the Boer War which began in 1899 in South Africa, to recent United Nations deployments.
Anton Coetzee, the Commerce Club general manager, said the club needed funds for essential repairs and maintenance to its Remuera building and members had decided with great reluctance to sell the painting.Mr Thomson estimated the painting would bring between $300,000 and $500,000.
The painting was likely to be protected under the Protected Objects Act, 1975, which meant it could not be taken out of New Zealand without ministerial approval - and that was given only in exceptional circumstances, he said.
The photograph is expected to fetch up to $20,000 at the auction which begins at 6.30pm.