Theon Design has marked its tenth year of air-cooled Porsche 911 restomods with a 964-based coupe in Oak Green Neo Metallic, built for a UK customer, that the company says delivers a better power-to-weight ratio than a contemporary 911 GT3 RS. The British firm also used the anniversary to launch an online configurator for its Theon R, Coupe and Targa models and a North American concierge service run through Humble House.
The build took 18 months to develop and assemble, with the owner making every specification choice, and it pairs a 419-horsepower naturally aspirated 4.0-litre air-cooled flat-six with carbon-fibre body panels and trim aimed at a curb weight of around 2,645 pounds. Theon quotes a 4.0-second run to 60 mph.
What the anniversary build changes under the skin
The starting point is a 964-generation 911, which Theon strips back before fitting what it describes as F1-grade carbon-fibre panels and interior trim. The weight target of roughly 2,645 pounds is a long way from many real-world 964s, which now sit closer to 3,300 pounds.
The engine makes 419 horsepower and 322 pound-feet of torque, run through drive-by-wire throttle control with selectable driving modes. Drive goes to a five-speed G50 manual gearbox, and Theon also builds a close-ratio six-speed for customers who want shorter gearing. The braking system is borrowed from the 993-generation 911 RS and is paired with Tractive semi-active dampers and spring rates tuned to this specific chassis.
Price, and what US buyers still have to sort themselves
Pricing starts at £435,000, or roughly $579,000, and most commissions climb past $600,000 once paint, trim and mechanical options are chosen. Theon does not soften the number: the company says it is a lot of money, but that the car is far more special than a similarly priced Lamborghini.
The concierge service gives American customers a local point of contact for the whole commissioning process rather than coordinating across an ocean. The cars are still built in the UK and imported, so buyers remain responsible for shipping, duties and local compliance work on top of the build itself.
That arrangement suits buyers who want the spec process handled closer to home but are content to leave import logistics to themselves or their own contacts. Until now, commissioning a Theon meant working directly with the shop in the UK, a process that favoured buyers already deep in the air-cooled 911 world. The configurator widens that: anyone can spec a Coupe, Targa or R from a computer before speaking to a Theon representative.
Theon R: confirmed power target, no arrival date
The more hardcore Theon R, which Theon says will top 500 horsepower, is currently in build. The company has not announced when the R will be completed or delivered, and it has not published a full set of output, weight or performance figures beyond that 500-horsepower target.
Theon is not alone in this corner of the market. Gunther Werks' GXR Evo and the Marc Philipp Gemballa Marsien GT push classic and modern Porsche platforms toward similarly steep prices and bespoke builds.
Why the US push matters
Restomod commissions have traditionally depended on a relationship with a workshop, which keeps the pool of buyers small and geographically narrow. A configurator plus a named North American concierge lowers the entry barrier without changing where the cars are made, so the practical difference for a US buyer is administrative rather than industrial.
The anniversary car itself shows where Theon's engineering effort goes: mass out, displacement and chassis hardware in. The power-to-weight claim is the company's own, and it is the figure that will define how the 964 build is judged against modern performance Porsches.
