If I remember rightly this was advertised a few years ago and the seller made clear then that it had been put together as a film prop and would need some modification to be road legal. This poses the interesting question; has it been brought up to proper road standards or is it just taking advantage of the MOT exemption?
Somebody must have insured it in order to tax it. I rather doubt the insurer is aware of the changes made to its original construction though!
When last advertised it was clear that a good deal of work had been carried out since the initial rather basic "film prop" modifications were first carried out but whether enough was done to make it truly roadworthy is open to debate. The car is not MOT'd and, in order to gain tax/MOT exemption I believe the vehicle has to be declared to have undergone no "substantial changes" within the last 30 years? This vehicle cannot claim that.