Brian discovered the cornet was made in 1925 and, realising it was the name of an American serviceman, Brian contacted the American Embassy in Wellington.
Within days he received a reply from one of Howard C Maxwell's three daughters, Karen Corbett, who said news of the cornet's surfacing had "created quite a stir across this country".
She confirmed her father was in New Zealand during the war.
"It is safe to say that all those who are in on the information here are shaking their heads in disbelief," she wrote.
"We knew he had given the cornet away. He had a habit of doing that. We have lost count of how many he bought and gave. I have the only one he did not give away."
She also confirmed that her father was recalled to the army in 1942, then sent to the Pacific and that, for a time, he was stationed in New Zealand, in his words, "to keep the Japanese navy from grabbing those two beautiful islands".
He returned to New Zealand after VJ Day before returning to the US.
Howard died in 1999, but as a result of Karen's search for information, members of her extended family have contacted one another after years of not being in touch.
While Brian has been sent a great deal about the cornet's wartime owner, the big mystery for him is where it has been since 1945.
The online seller, from Hamilton, bought it at a garage sale and has no idea where it might have been all those years.
Brian has followed a couple of leads to dead ends, but is still keen to solve the mystery.
He doesn't regard himself as a serious collector, but likes to buy and sell instruments.
"Some turn out to be dogs, some turn out to be quite beautiful," he says.
A freelance brass player, his background is in brass bands, but he also plays with Bay Dixie and the Woody Woodhouse Connection.
Anyone who might be able to help
can contact him at briangail@kinect.co.nz
