Built in 1926 by the Napier Fire Board, it housed the fire brigade until 1968 when Mr Natusch bought it.
"It was derelict and I thought, 'this is a good building - we could make a design centre out of it'."
His plan was successful and the building was fully tenanted.
"It really was a very nice anchorage at that end of town.
"Then I let Art Deco come into it, because they had nowhere to go."
The 92-year-old said the Art Deco Centre had expanded over the years to become the main tenant, but had moved to be closer to tourist attractions on Marine Parade.
He was reluctant to add to the partial tenancy himself, unless it was a tenant "that helps Napier".
Property Brokers agent Wayne Parsons said the building could once again be a multiple-tenanted centre and Mr Natusch said the Historic Places Trust was keen to work with the building's new owner, to ensure its viability.
"Any changes need to be proposed to the Historic Places Trust for their consideration, it then depends on what aspects of the building they would like to protect," he said.
A full seismic report would be available to prospective purchasers as well as costings to improve its current High Grade C rating, if desired.
Mr Natusch said he would not have bought the building in the first place"unless it was structurally sound and a good investment".
The property's land area is 1,029sq m, floor area 811sq m (partially tenanted) with 18 car parks.
Mr Natusch said he plans to attend the October 17 auction in person.