I second Hagerty: ace service. That ebay car.... my god.... there are a number of fixed checks to do with a standard 911, but this one needs an expert.
1. Q plate- identity problem? Why? Each porsche has a year indicator in its chassis number? So why can't it get age verified? Fraud? VIN tampering? Accident repaired? Imported from where and in what condition? Is the car imported the car that is *physically* offered on ebay etc?
2. in 1987 there was already the G50 box- that car is equipped with the pre-aug 1986 915 box according to the discription. Something funny going on there.
3. Is it an original supersport widebody 3.2 carrera with the turbo brakes, suspension, sports equipment and sports seats or a 911 of unknown origin that has been "build up with wide arches"?
4. 964 kit- okay a popular modification in the early 1990-ties and beyond. But what quality of parts used? Cheapo GRP stuff or high quality porsche german quality?
5. An old 911 hardly dies- there is always someone foolish enough to sink time, money and effort into it. This seems such an old 911. They all cost money, but if kept in original condition, maintained by an aircooled trained-by-porsche-in-period technician AND USED REGULARLY, they cost per annum something like £300 to £850 to run. Every 3 years a big spend of £3000 approximately.
This car has not been driven for a long while, so expect ALL the engine/gearbox rubbers, bushings being dried out. Drive 300 miles and stored it in your garage and you can mop up an oil leak of 1,5 litres. Suspension bushes? Sloppy gearbox?
There is a landmark difference between a porsche 911 that passes it MOT and one that is, say, 90% as Porsche intended it.
A gullable newbie is the perfect victim!
This is a car for someone who knows what the sum of the parts is on this car, and can do a lot of work themselves. This doesn't seem to be a car for a novice.
6. 12k can provide you a very very good 911 SC 204 bhp or a 3.2 carrera that requires work in the next two years. Go for something with a cast iron history, owned by someone who cared for the car and who USED the car regularly.
7. I also second online forums such as www.impactbumpers.com for additional advice. You've got a lot of reading to do, and the book by Peter Morgan "the original 911" is a good start!
Best of luck in your search and keep us posted,
Bert