"Many historical sites in Paihia have been lost, with buildings taken down to erect more modern ones. So much of the history is not visible," Andrews said.
"There are some old signs, which need replacing or further development, so we realised we had to add a great deal to what was already there."
PHLS has also received major contributions from the Frimley Foundation, the JN Williams Trust, plus support from Focus Paihia, and as such now has a budget of $600,000.
"The advancement of this project marks the first big step in a series of future developments," Andrews said.
Waitangi Marae chairman and Uri O Te Kemara (descendant of Te Kemara) Ngati Kawa Taituha said the legacy trail would celebrate the bond between the two cultures, which had been crucial to the signing of the 1835 Declaration of Independence and the ensuing Te Tiriti o Waitangi/Treaty of Waitangi.
Te Kemara was the first speaker at the hui with William Hobson when he presented Te Tiriti in 1840.
Taituha acknowledged his whakapapa as a descendant of Te Kemara, and said he had taken on the role of cultural content creator for the trail project with passion and pride.
He said he expected some of the stories highlighted by the trail walk may not be easy for everyone to accept, and even controversial.
"But we can't pretend the history is all a happy one when it clearly was not," he said.
"What we can do is learn from the past to make a better future for Aotearoa, as intended through the visionary foresight of both Māori and the missionaries when Te Tiriti was drafted and signed.
"The trail will bring forth the revelations of the past to help us reconcile the relationships of the future."
Taituha said he valued the collaborative involvement of tangata whenua, Focus Paihia and the Williams family reunion committee.
"The bicentennial will be commemorated in a way that enhances the mana [status] of everyone involved," Taituha said.
"This foundational mahi [work] encapsulates the spirit of Te Tiriti o Waitangi 1840."
In 1823, following an invitation from Ana Hamu from the hapu Ngāti Kawa me Ngāti Rāhiri, Henry Williams arrived to establish the Church Mission Station in Paihia.
Hamu and her husband Te Koki sent their son to live with Samuel Marsden in Sydney to attend the CMS Christian School.
While there and in the formal care of Marsden, their son died.
From a Māori perspective, this created a customary obligation that influenced Marsden and Williams' decision to choose Paihia as the site and location of the Church Mission Station.
Its original purpose was to serve as an education centre for tangata whenua.
According to PHLS, the significance of early engagement between Maori and Europeans at Paihia went beyond religious conversion - they also extended to discussions on how the two cultures would manage living side by side into the future.
What began there set up a chain of events that would ultimately lead across the river to Waitangi, and the signing of Te Tiriti - set to celebrate its bicentenary in 2040.
PHLS chairman Martin Williams said the trail would interest not only tourists and those interested in history, but - crucially - students, whether visiting Waitangi or studying from home.
"It captures the imagination and piques the interest. It's meant to be fun," Williams said.
"Think of a year 10 student. It'll prove much more engaging than a textbook.
"It's an effective point of entry, and can lead to natural interest in further exploration of our history."
Williams described the project as being about much more than the important upcoming dates.
"It really is about correcting the understanding of history, so people can then come to comprehend the opportunity that the treaty represented, and what the intentions were in drafting it," Williams said.
"The history can't stay wrong for the next 100 years."
PHLS hopes to have completed the trail by April 2023.
