One very nice air-cooled Porsche 911, set to be auctioned in October.

Porsche has unveiled its resto-modded Project Gold 911 Turbo, with a brand new 3.6-litre turbocharged flat six engine wrapped up in a lovingly-restored 993 Turbo body.

The one-off reportedly took 18 months to create, using a combination of original, restored and 'new' parts. Both the transmission and all-wheel drive system are from the Porsche Classic catalogue, while the aluminium chassis – a first for the 911 when the car was initially released – was stamped by hand for Project Gold.

While we're talking firsts, the 993 Turbo was also the first twin-turbo 911. Although the Project Gold car has a brand-new engine, built from the ground up by Porsche Classic, it makes the same 335kW as the original. Oh, and it's air-cooled. Obviously.

There are plenty of bespoke touches around the car, starting with the gold pinstripe on the hollow-spoke wheels. They're painted black, before a laser is used to remove a layer and create a distinctive stripe. Meanwhile, the body is finished using the same 'cathodic dip' process as modern cars, for a better finish than the original.

Black and gold is the theme inside, too, where the original interior has been re-trimmed with black leather and gold stitching on the seats, dash and steering wheel. It all looks period correct, from the radio to the classic five-dial instrument binnacle, although we'd bank on the materials in Gold being a bit nicer.

Although it isn't road legal, Project Gold will be auctioned at RM Sotheby's Porsche 70th Anniversary Sale on October 27. Given the 993 Turbo is already a sought-after beast, this one is likely to command a crazy price.

Head to the galleries section for more images