Questions about importing and NOVA (classic car)

[dieselnutjob]

Hi

I'm looking at import a 1978 Peugeot from France.
The car is in good condition, roadworthy with a current Controle Technique and Carte Gris in the old french owners name.
I have some questions.

Is the duty purely the VAT at 5% of the value?

How does HMRC determine the value?

Is it legal for a UK resident to drive a car on French plates in the UK if it's going through NOVA?

Once the VAT is paid is there a time limit to register the car?
what would happen if I put the car away into storage until I get round to it?
what would happen if I export it back to another EU country, but with the VAT already paid? does this leave me free to bring it to the UK again later in time tax free because it was already paid?

thanks