The DVLA are useless.....They couldnt get my address right after two attempts and had the cars details mis-spelt too...Every time i have been in contact with them they have cocked something up....
So just reshell it, Dont involve the DVLA but do a proper job on it using Ford only parts and dont cut any corners, its basically the same car anyway as all the parts of your cirrent 3dr are there...
The DVLA will only cock things up and leave you in the lurch!