Corrections staff would prefer Mr Magill to keep Wilson out of the media, but he said media exposure could help.
"They've got to be very cautious, and I respect them from that point of view. But you've got a man that's had a horrific background and he will respond to community support."
He is encouraging Wilson to write a book about his life in institutions, including time in psychiatric hospitals. The Crown Health Planning Agency has sent Wilson a letter of apology for the way he was treated.
Mr Magill, a Justice of the Peace and self-appointed "Napier Community Mentor", is a campaigner for social justice and "a better understanding of each other's journeys". He said Kiwis were too keen to punish without trying to understand.
Last Friday, Wilson cooked him a lunch of steak, eggs and onions and showed him his garden. They spent four hours together, before 88-year-old Mr Magill hitchhiked back to Wanganui. Wilson had impressive skills in both gardening and fishing, he said.
His visits to Wanganui have convinced him it is the right place to set a national example in treating people - including prisoners - humanely.
He is impressed by the work of Steve Treloar from Wanganui Prisoners' Aid and Rehabilitation Trust. Mr Treloar's wrap-around care was one of the best models in the country, Mr Magill said, but was worried its funding might be cut off.
He sees the Te Araroa Trail, which passes through the city, as another plus - an "affordable Outward Bound". And he has stories about how people change for the better after walking it - especially if they are with others from a different way of life.
Annette Main, Wanganui's "restorative mayor", was another asset, Mr Magill said, as was the city's experience with restorative justice and its Restorative Practices Trust.
He sees the city's small size, parochialism and "honest poverty" as more pluses.
Mr Magill plans to walk parts of Te Araroa, and wants to be part of a group heading through Wanganui to Ratana Pa on the national trail in time for the annual Ratana celebrations next January.
A retired businessman and former Hawke's Bay Rugby Union president, he was a Senior New Zealander of the Year finalist in 2012.
He said he is just "sticking to my knitting".
"I'm not a do-gooder. This is real community development."
