For the last two years Mr Cavanagh has been back in his home town, bringing the CSI brand to the city. CSI stands for Complete Security and Installation, and is the company he and Andrew Marsh formed in Wellington. Mr Marsh still runs the capital city operation.
Since returning home with his wife and family, Mr Cavanagh has been working remotely but has now opened a shop in Guyton St to raise the company profile.
"I was always comfortable I could do all right opening up in Whanganui, given there's only one other locksmith company of note in the city," he said.
On his own at this stage, he hopes to employ a staffer in the near future once the business beds in.
"Primarily our expertise is in locksmithing and hardware installation. We'll install all the door hardware for the main building contractor. If the contract is too big for me to handle alone, I can get help from our Wellington operation."
He said hardware installation was a very small but specialised part of a building contract, but was complex "and if you get it wrong it can muck up an entire contract".
But he said CSI had built a reputation with major construction companies like Fletchers and Hawkins, so this was not foreign territory to him.
As well as keys, locks and safes, Mr Cavanagh sells security bollards and security grilles. "We're the NZ agent for a UK-made expanding security grille. It's the grille the British Home Office uses in all its embassies and high commissions around the world."
If security alarms or CCTV is needed, he's got other suppliers he can call on.
Having worked overseas, he said Kiwis were nowhere near as security conscious as people in the UK.
"I reckon we'd be about 30 years behind where they are in terms of security. The hardware we were selling to people when I was in London in 2000, you still wouldn't see it here because locals are not that concerned.
"But you can't go to Mitre 10 or Bunnings and spend $10 for a door lock and expect that to secure the hundreds of thousands of dollars of assets inside your house. So it's about changing people's mindsets around it."
Mr Cavanagh said he wanted to provide a good-quality service and advice on security.
"It's about giving people the right product at the right price. It's all about quality service and that's what I've prided myself on, and how our company built its reputation."