Project Marton is a tenant of one of the buildings and co-ordinator Cath Ash said everyone wanted to know who the new owner was.
The buildings are 304-318 Broadway and 4-10 High St, and surround the Marton office of Property Brokers, a branch of the Property Brokers real estate company owned by Mr Mordaunt.
In his submission to Rangitikei District Council he said they were an earthquake risk and in poor repair.
They shared party walls with his own building and endangered staff in his office.
Their former owner is Adam Wade, trading as Actual C Properties Ltd, and they have been up for mortgagee sale for a year, with no interest from buyers.
Mr Mordaunt wanted to demolish all of the buildings on that corner and replace them with a large, modern, one-storey retail building. Demolition would need resource consent from council, and he was only willing to embark on the project with council support.
Council environmental services manager Stephen Costelloe said he would likely have got that support.
The buildings were listed for protection in the council's district plan, but it was also keen for development.
"There's not much development pressure, so if somebody actually wants to do something we really would be keen to see them do it."
Rangitikei had an even bigger problem than Wanganui with earthquake-prone buildings. There were two-storey heritage buildings in Bulls, Marton, Hunterville, Mangaweka and Taihape that needed earthquake strengthening. Their owners were unlikely to do it, because it was hard to tenant the buildings and make a return.
The Marton buildings surrounding the Property Brokers office, known variously as the Cobbler, Abraham and Williams buildings, have a Category 2 New Zealand Historic Places Trust registration and were built around 1913.
Rangitikei resident Howard said the Cobbler Building on High St was a former coach stop.
"It's fairly key to the history of the town. If that could be demolished and redeveloped it could set a precedent for every other building in the main street of Marton."
It had escaped demolition at least once before, she said.
Historic Places Trust spokesman David Watt said the buildings made up a landmark corner and were a significant contributor to Broadway's Edwardian character. They were two of 18 heritage buildings in central Marton listed on the council's district plan.
He said there were new and cheaper ways of strengthening unreinforced brick buildings, and Government may offer tax incentives for doing it.
Other towns had found ways to turn their fortunes around - he cited Shannon, Greytown and Tirau.