Dunedin city councillors this week decided that the museum would close from May 1 until its $35 million redevelopment project was completed and a "grand reopening" staged next year.
Museum authorities have emphasised that although the two remaining small public displays at the city council-owned museum will close, the museum's education, school holiday and other special programmes will continue.
Mr McNulty is the managing director of Classic Jaguar Limousines, a firm which has been bringing pre-booked tourists, including cruise ship visitors, to the museum for more than a decade.
It was disappointing the museum would be closed for 18 months but the result would be a "fantastic venue" and an "amazing and magnificent" facility once the redevelopment was complete.
He was keen to continue to tell Dunedin's Scottish story to overseas visitors, and was now making alternative stops at nearby First Church and the Dunedin Railway Station.
It could take some time and effort for the museum to reconnect with the cruise industry after it reopened but he was optimistic that would be achieved.
Museum director Linda Wigley said museum staff were carrying out a "mammoth job" involving the redevelopment and a "huge amount" of activities involving the public would continue, although the museum complex would be mainly closed.
Asked whether such a long closure called into question the point of having such a museum, Ms Wigley said that was not the case.
Asked about a potential merger with the Otago Museum, she said the two museums had operated successfully with a different focus for more than a hundred years and were likely to continue to thrive as separate operations for a further century.
The redeveloped settlers museum would be "bigger, brighter and more dynamic".
Museum staff had a "duty of care to the collection", including to take down portrait photographs in the museum's Smith Gallery, to protect them from dust and other hazards generated while the museum was a construction site.
The museum had also been working with Dunedin firm Areo to develop some "very exciting" possibilities for after the museum exhibitions closed.
The firm had been developing an electronic kiosk where members of the public could view of a "virtual" Smith Gallery, and the museum's Internet site would also be redeveloped from May 1, she said.
City heritage advocate Elizabeth Kerr was not disappointed the museum would be closing, given the big challenges faced.
The eventual results would be outstanding and she believed the public would be astonished by the redeveloped facility, she said.
Cr Bill Acklin, who chairs the council's community development committee, said the nearby Dunedin Chinese Garden could be visited as an alternative attraction while the museum was closed.