He won't say how much it's cost him since he ventured to New York in 1974 to meet ex-patriate Lye and bringing back some of his designs to experiment with and build.
Lye was so thrilled by Matthews' efforts he bequeathed much of his life's work to New Plymouth.
Matthews has continued to make and sponsor the making of 19 of Lye's 30-odd steel sculptures, often through his alma mater, the Canterbury University College of Engineering, which is about to confer on him an honorary doctorate for his efforts.
Building the Len Lye Centre has been Matthews' dream since the time Lye talked to him of the need for a "temple" to house giant versions of his motorised sculptures.
Although the $11.5 million needed to build the centre has come entirely from the fund-raising efforts of Matthews, the Len Lye Foundation and the associated Len Lye Centre Trust, the 2013 local body elections saw many district councillors turfed out because of what a determined bunch of ratepayers saw as over-spending, especially on things like the Len Lye Centre.
One to lose his seat was the chairman of the council's Len Lye committee, Lance Girling-Butcher. A particular gripe was the decision not to charge an entry fee.
Since then, local residents have complained to the council about what turns out to have been someone's misguided calculation -- that the Len Lye would add $650,000 a year to the adjoining Govett-Brewster Art Gallery's annual running costs.
In fact, the council now believes the additional cost will be less than $200,000, a small price to pay for what it believes will be an international attraction for arts trail tourists.
A recent report by Business and Economic Research reckons the Govett-Brewster's pre-Len Lye Centre visitor tally of 70,000 a year (most of them to see Lye's works) will jump to 100,000, 60 per cent of them from out of town.
The opening exhibition will feature four versions of the sculpture Fountain, the largest and newest of which spans nine metres and dominates the first great gallery of the centre.
This space is reached via a polished concrete ramp that rises gently alongside the inside of the building's columns, whose exterior carry the 32 tonnes of stainless steel cladding already made famous by photographers chronicling their gradual unveiling from behind the scaffolding.
Another ramp takes viewers to a second vast gallery, where other Lye sculptures will be set up, including Grass, Universe, and Roundhead, a work that incorporates Lye's wife Ann's wedding ring.
A new version of Trilogy: Flip and Two Twisters will be hung in the Govett-Brewster in an eight-metre tall gallery where a previous incarnation startled visitors with its deafening crescendos.
At this stage there are no plans to show Blade, a sculpture that is notorious - according to Matthews - for inducing orgasms in female viewers.
Meantime, Brian Hannam, an Auckland playwright and producer, is talking of reviving a long-lost play about Lye, a sole-performer production that he researched and wrote more than a decade ago but which has never been performed publicly.
The centre will be opened on Saturday July 25, by Minister of Arts, Culture and Heritage Maggie Barry and Economics Development Minister Steven Joyce, who in a past life began a radio empire with a start-up station in New Plymouth.
There will be performances from members of the Auckland Philharmonia Orchestra accompanying Lye's cinematic and kinetic sculpture works.
The film show will launch with a screening of Lye's first film, Tusalava (1929) and a film by Leon Narbey, documenting his own exhibition, Real Time, at the 1970 opening of the Govett-Brewster.
The doors will open to the public from 10am tomorrow.
The opening programme can be found here.
