Nearly 150 years ago to the day that a rescue party found John King, the sole surviving member of the expedition, Sue Weekes was able to get a first-hand look at a pistol that was once owned by William Wills.

The firearm was donated to the State Library of Victoria in 1947 by Mrs Weekes' father Ronald Cooling.

It was one of a number of artefacts on display during the library's Travelling Treasures exhibition in Warrnambool last night.

Although she knew the pistol and some of Wills' other belongings had been handed over by her father for safekeeping, Mrs Weekes had no idea of their whereabouts until she read an article about the exhibition in last Wednesday's edition of The Standard.

"I think it's just such an exciting find," Mrs Weekes said yesterday. "I'm all revved up to look into the family history now."

The retired school teacher said her great-grandfather Carl Moerlin was a German immigrant and astronomer who arrived in Australia about 1860 to take up an appointment as second-in-charge at the Melbourne Observatory.

William Wills arrived in Australia from England in 1853, working at a sheep station and later training as a surveyor before joining the staff at the observatory, where he became good friends with Mr Moerlin.

After Wills died on the banks of Coopers Creek in June 1861, his possessions were handed over to his best friend, Mr Moerlin.

Mr Moerlin was married in 1862 and his only child, a daughter, Helen Edith Moerlin, was born the following year.

Helen married Richard William Cooling and the couple subsequently had nine children. Mrs Weekes' father, Ronald, was the youngest.

Mrs Weekes said the Wills' artefacts were handed down to her grandmother, but the pistol was stolen from the family home in 1944.

Police recovered the items, but the pistol had been damaged, with a section of its barrel missing.

When her grandmother died in 1947, the items then came into the possession of Ronald. Recognising the pistol's significance and fearing the items were not in a secure location, he decided to donate all the artefacts to the library.

Travelling Treasures tour manager Cameron Hocking said for quite some time the firearm was believed to be the pistol that Wills took with him on the expedition to the gulf. Research had since shown it was more likely to have belonged to Wills when he worked at the observatory, he said.

However, it is more likely that the pistol, a Belgian pin fire revolver, belonged to Wills when he worked in Melbourne before the expedition.

All of the men on the expedition were issued with a firearm from the government stores. Wills was issued with a Colt pocket pistol, which is also in the State Library's collections.

On his return to Melbourne, John King said that Wills had given Robert Burke his pistol as he set out by himself from Cooper's Creek, as Burke's own gun had been lost. That pistol was reportedly found in Burke's hand when his body was recovered in September 1861.