During his trial, Maguire denied the offending took place, instead blaming adults for "procuring the girls to make it all up".
Maguire still maintains his innocence.
Justice Miller said this was "unhelpful" for Maguire in sentencing, as it contributed to his risk of reoffending, reduced the likelihood he would receive treatment in prison and meant he could not have remorse for his crimes.
Justice Miller said Maguire lived a "transient existence", living in house buses or caravans with a loose community Maguire described as his "clan".
"You presented as a friendly uncle or grandfather type, and the parents regularly entrusted the children to your care," he said.
Maguire had an "interesting but troubling history", Justice Miller said in his sentencing notes.
``You report being born into one of the biggest criminal families in New Zealand,'' he said.
Maguire's family lived as ``showies'', running amusement rides at carnivals around the country.
Justice Miller said there were obvious similarities with Maguire's present lifestyle as a self-described ``house trucker''.
Maguire had what was described as an ``extensive and versatile history of offending'', beginning with a conviction for unlawfully taking a bicycle in 1963 at the age of 16.
``You have gone on to acquire 93 convictions, 75 of those pre-dating the present ones,'' Justice Miller said.
These included a 1990 conviction on two charges of intercourse with a girl aged 12-16, from a relationship with a 13-year-old who became pregnant with his baby.
In sentencing, Justice Miller said Maguire's risk of reoffending is high, with pre-pubescent or adolescent females known to him most at risk.
The Crown had asked Justice Miller to impose a minimum sentence but the judge opted to leave the Parole Board with the flexibility to assess when Maguire should be released.
Justice Miller warned Maguire this should not be interpreted as a sign he would receive parole, as he was unlikely to be released while the board considered him likely to reoffend.
- nzherald.co.nz