"It really felt like the ancestors were with me," he said just after becoming the first Gweagal man in almost 250 years to hold the shield taken from the shores of what is now called Botany Bay.

"I felt so proud, but then it was upsetting to walk away. It was amazing to feel it, and hold it."

After more than three years of negotiations with the museum and multiple trips to Europe, Mr Kelly is getting used to the ways of the culture that invaded his own more than two centuries ago.

"Why I feel so strongly about getting the Gweagal shield repatriated is that it tells the story of that first day in 1770. It shows that we were fired upon, while [Lieutenant James] Cook was in his boats," the Bermagui resident said.

"To give a culture back its history. To give a culture back some pride. To give a culture back a learning process, so they can learn how it was done for thousands and thousands of years. I say that is a real powerful thing.

"It's hard to understand how they can value our cultural items, but never had respect for us I think they were just trophies of a land they conquered.

"I have to play my part and help others reclaim there history. Soon there will be too many of us, so they will have to change."

Mr Kelly's ancestor, the Gweagal warrior Cooman, was one of those men on the shore as Cook's marines approached, before retreating after being fired upon aggressively by marines.

Normally kept on display inside a glass case, Mr Kelly said there is white and red ochre on the shield which he says smells of old burnt wood and has two horizontal and two vertical lines drawn with charcoal.

"I didn't expect to see the pattern on the back in charcoal, but it was everything I thought it would be. So amazing and special," he said.

The museum allowed Mr Kelly to view the shield, which has become synonymous with his efforts to have artefacts throughout Europe repatriated, along with other objects taken from Sydney and now kept in storage, including four other shields and two boomerangs.

"I did tell them they need to get some elders from each state to go in and catalogue what they have, and maybe they could put a state or tribe for where it came from. They liked the idea," he said.

"I also spoke to them about making videos of people talking, so visitors can learn more about what they are looking at. They said that it's a good possibility they can do that."

Mr Kelly was also shown a rare lithograph of Timbere, who lived in what became Port Jackson from 1784 to 1840.

A lithograph of Timbere by Jacques Etienne Victor Arago in 1822 was purchased by the National Portrait Gallery in 2011.

The museum has told Mr Kelly they are prevented by law from returning antiquities and artworks, however he said one British politician has told him they are hoping to change that.

Nicholas Thomas from the University of Cambridge Museum of Archaeology and Anthropology published a paper last year disputing the narrative suggested by the British Museum and Mr Kelly. Mr Kelly has previously called the paper "propaganda put there to cast doubt on the provenance of the shield".

"We are aware that some communities have expressed an interest in having objects on display closer to their originating community and we are always willing to see where we can collaborate to achieve this," the museum has said.

Mr Kelly is also attempting to repatriate a number of spears being kept in the Cambridge Museum of Archeology and Anthropology as property of Trinity College, as well as artefacts in Sweden and Germany.

This month's trip was the best yet, he said, with 300 people attending an unofficial "Stolen Goods" tour of the British Museum on May 4 organised by activists "BP or not BP", who are protesting the company's sponsorship deals with the institution.

"Talks from Palestinian, Iraqi, Greek and Indigenous Australian activists joined the dots between the repatriation of stolen artefacts, ethical sponsorship of the arts and the climate crisis," the group said.

During the tour, Mr Kelly told onlookers about life as a Gweagal man under colonial rule.

"We had everything stolen - shields, spears," he said.

"It's important because Australia is a racist place that didn't treat us as humans from the start. People need to know the real history of what happened.

"We can learn so much from studying this shield. It's time the British Museum took this request seriously.

"I grew up without an identity as we weren't allowed to learn about our culture. That's why this shield is so important. It's a symbol of our resistance to colonisation."

Support has been growing during his trips to Europe, and lectures with university students has lead to one looking to complete a Masters degree on his efforts.

"They [the British Museum] have had those shields for so long, but they were asking me about them, trying to learn from me," Mr Kelly said.