In many ways, the 1963-1969 S-Type was a bit  of a stop gap for Jaguar, built to plug the gap between the compact Mk II and the gargantuan Mk X.

It was a hybrid of both of them, with the entire front end and powertrain of the Mk II, but with the rear suspension of the bigger Mk X, mounted on an extended Mk II body that retained the same front panels but had a lengthened rear end, with a much larger boot. 

The flagship S-Type was the 3.8, which used the same engine as the E-Type sports car and was a highly desirable and rapid sports saloon. A delectable combination of power and prestige. 

And that’s what we have here, though this car’s glory days are (at present) a long way behind it. Indeed, it’s looking a bit sorry for itself. 

This is a complete restoration project whose rebuild was started by its long-term owner, but he was never able to complete it. But, it’s all there. It’s complete, there are four boxes of spare parts and stacks of history. KPF 602C deserves to live again – it just needs a skilled owner to take on the task of bringing it back to life.

Up until last year, the Jaguar had been with the same keeper for almost four decades. He acquired the car in 1983 from its second owner and used it as his own car for several years before it failed one too many MOTs and was parked up in need of repairs.

Life took over, and while the previous owner had other cars to use for day-to-day transport, the Jaguar always stayed, parked in a corner as something he’d get round to ‘one day’.

That day came in 2018 and the previous keeper went on a spending spree, spending £3,000 buying lots of parts for the S-Type, on engine repairs and going as far as to get the front end of the car pretty much sorted out, with new crossmembers, suspension and brakes. 

Sadly, after owning the car for almost 40 years, the owner found himself in a position where he was unable to complete the work himself and it was acquired by the vendor, who took it on as a project but has never really had the time to get stuck into it.

The sub-50,000 mileage is believed to be genuine.

There is a full record of the vehicle’s ownership, including a photocopy of the original buff log book, an old-style V5 and a new one.

There’s also a huge file of bills and receipts relating to the car’s past – lots from 2018 for new parts from a very well-known Jaguar parts supplier, which in turn document the work carried out on the front chassis, brakes and suspension, as well as some mechanical parts fitted in order to get the Jaguar running again.

Of purely historical interest, there are also some much older bills that relate to work carried out on the car in 1979 and 1980, including a new pair of sills (now mostly gone…) And what appears to be a fairly substantial mechanical overhaul with a number of the parts bought from Loxley's of Bromley - at the time, a very well-known BL Cars dealer in the Greater London area.

From a distance, the S-Type really doesn't look too bad. But the closer you get, the more work you start to see.

There are the more obvious faults such as a large dent in one wing, frilly door bottoms, tarnished chrome and down-at-heel paint, while it is quite clear that the Jaguar will need complete sill replacement on both sides and also some fairly substantial welding repairs inside both rear wheel arch sections.

But, you know what? If you can see past those obvious faults there are a lot of positives. The floorpans are in good order and there's no rot to be seen in the boot floor, which is a common area for corrosion. KPF 602C is rough, yes, but it's by no means a basket case. 

As a basis for a ground up restoration, there's a whole lot to like.

As with the exterior, the interior is scruffy and the work that it needs doesn't try to hide itself. Also like the exterior, pretty much everything is there. Indeed, the rear seat is in excellent order and the fronts, albeit worn and with some damage, are certainly not beyond repair.

Quite a lot of the wood is salvageable, so while the car will need new carpets and a partial retrim, it's actually a lot better than it could be. With the right level of vision, this could be transformed into a lovely car.

According to the vendor, the S-Type is actually in good running order and he's been able to drive it on private land. He says it runs well and goes in all gears, while the work carried out by the previous owner on the front suspension and brakes is one less mechanical challenge for the next owner.

It's the 3.8-litre XK engine that is core to this car's appeal. The very same engine as used in the 150mph E-Type and one of the most impressive high performance engines of its day. It turns the S-Type into a lovely high speed cruising machine, though it'll be a while before this car sees motorway speed limits once more. 

Quite apart from the bodywork and chassis needing repairs, it will require a rear suspension overhaul, new rear brakes and a full engine check over and service before it can be driven in safety and with confidence.

Make no mistake, this car is a total restoration project and to see its full potential requires a bit of vision. However, it's all there, and once you get past its obvious scruffiness, the list of positives gets longer and longer, especially when you look at its impressive history and the fact it has come from an owner who had it for four decades.

This is a car that deserves to live again, and while it's not a restoration job for the faint-hearted, it's one that will deliver a lot of satisfaction to a knowledgeable owner who takes it on.