It would also have interactive screens where people could research battalion soldiers.
''It'll be a really beautiful place to come and reflect,'' McManus said.
The starting point for the museum was the February 6, 1940 speech by Sir Apirana Ngata in which he argued that serving in World War II was "the price of citizenship".
''That's why the museum is at Waitangi. It can't be anywhere else,'' McManus said.
A separate multipurpose building behind the museum would include a commercial kitchen, a dining area for up to 200 people and staff offices.
It would be used to host official groups instead of the marquee used on Waitangi Day in the past as well as for school visits.
McManus was confident the museum would be ready by February 5 and hoped the battalion's surviving veterans, Robert "Bom" Gillies (Rotorua, B Company) and Epineha Ratapu (Masterton, C Company), would be able to take part in the opening ceremony.
As much work as possible was being done by Northland firms, he said.
The museum had been designed by Grant Harris of Whangārei's HB Architecture and was being built by Henwood Builders of Kaikohe. The tilt slab panels had been made in Kerikeri and the steel framing in Haruru Falls, while Whangārei's Te Warahi Hetaraka was carving the waharoa (gateway).
The museum would add to visitors' experience at Waitangi and encourage people to stay longer and spend more in the Bay of Islands.
''But the main driver for me is that a lot of New Zealanders and international visitors don't have a good understanding of the Māori commitment in terms of war. Māori didn't have to go to war, they were all volunteers and they paid the ultimate price. They had the highest casualty rate of any New Zealand battalion,'' McManus said.
Regional Development Minister Shane Jones said he was ''mightily pleased'' to learn the project was so far on schedule and under budget.
''Obviously it's a challenge getting it ready for Waitangi Day 2020 but I was assured that will happen.''
Jones was also pleased to see many young locals working on the project. About 25 people were currently working on site with that number expected to rise to 78. Other firms in the area had benefited with orders for steel and concrete slabs.
The minister said there had been some concerns from people on the East Coast that the project could eclipse their C Company museum, but that would not be the case.
''There will be a unique position occupied by A Company but it will be very inclusive. It will be a place where Kiwis and international visitors can come and share some of the knowledge of one of the defining features of out nation's history, and that was the creation of the Māori Battalion.''