He also has another one or two in storage for friends, all largely original, boasting the gorgeous patina developed by ageing wood and leather, and all British.
He put Land Rover rear shocks on the Aston, kept the original Konis, and had the fronts rebuilt with higher compression, so it's a bit stiffer, and fitted softer brake pads.
Specification is as generous as you'd expect from a luxury GT, with air conditioning, a radio, electric windows and a button for a heated window, though Butler says it doesn't appear to have one. There's the full range of gauges and a fly-off handbrake - "that's what I call it, anyway" - plus the original three-speed auto and 5.3-litre engine. He says power is rarely quoted, "but it's 240kW or thereabouts", though it's the torque you notice.
Clive Butler's 1977 Aston Martin AMV8 grips and corners with a precision and confidence that suggests it's capable of going much faster.At first that mighty engine sounds harsh and it takes a while to warm up. These cars started out with fuel injection, "I think Lucas, but it didn't work right so they put Weber carbs on, though you have to look after them to get them working right."
The original manual says to press the accelerator two or three times when starting from cold and hold it at 2000rpm for 20 seconds. "That doesn't seem right but you do have to warm the plugs as there's so much petrol going through."
Butler averages 15l/100km driving to Taupo but closer to 23l/100km round town for an average of around 20l, "depending on how you drive!"
Once the engine is warm it will cruise along happily at 50km/h in top gear, and Butler soon pulls over and hands me the keys.
Adjusting the seat, and threading the seatbelt round the door-mounted armrest, I turn the key to liberate a rich, rolling idle. Select "drive", and we're off, the engine grumbling and mumbling as we tool through the urban fringe.
Butler wasn't kidding about the hard brakes. They're not dead and they respond well once they bite, but you need strong thigh muscles to get them working.
Pulling away from a junction I plant the accelerator. It's not quick compared with modern cars but it makes your hair stand on end and I quickly get friendly with the throttle. And you can, for it handles well - I'm relatively sedate as it's very much not my car, but the steering feels precise, and it grips and corners with an entirely unexpected precision and confidence that suggests I could go quite a bit faster. "It's a GT really, not a sports car but the faster it goes, the better it feels," he says.
I still can't believe he might sell the Aston, but he's a member of six car clubs, president of one, and he's not driving it enough. "Having a lot of cars, I have to make sure they're all going, at least once a month."
Sounds like a good problem to have, and even better that his wife's happy he spends his days in the shed. "She thought I'd be under her feet when I retired but I'm here all day most days," he says, smiling as he looks at the ranks of shelved Alvis parts, the rows of partially complete cars, and at this gleaming, muscular thoroughbred parked in pride of place among them.