The interiors of many Spitfires have been neglected and can be in poor condition, some have been subjected to some creative modifications. The best situation is to find a complete, but well-worn, original interior. On most un-restored Spitfires you should expect to spend a considerable amount of time and or money bringing the interior to original (or better) condition. Most items area available from leather seats, carpets to door cards however these will be expensive but worth it in the long run. The Spitfire already has a wooden dashboard and this must be checked to make sure it is not suffering from water damage or is delaminating. Replacement wooden dashboards are available in the original finish and other finishes such as walnut can also be fitted. You can even upgrade your steering wheel and many different types and styles are available to suit your interior.
An un-restored car is also likely to need a new soft top as the vinyl tops tend to get torn from improper folding and storage so check carefully for rips etc unless you intend to change the soft top. The top frames are ruggedly designed and even those that do not raise and lower smoothly can be cured with some good lubricant. New soft tops are available now and in a larger range of materials and colours than when the car was new and are quite cheap for a replacement vinyl rising to more expensive mohair type..
The interior of the car is where you will get the most out of your driving experience so it is worth spending extra, also if the interior is a bit scruffy when you are buying then it is a good lever to get the price down.