Pete is right. It's not illegal to do a cut and shut. However, two things spring to mind:

1. Where is the original stamped in chassis number. One half of the car must still have it?
2. Not sure that the car would behave as ford intended in an accident as it was never meant to have a big weld from one side to the other.

As for Q plates, yes you can still get them as far as I'm aware. Not all police forces have the same policies on unidentifiable cars. Some have stamp and return policies in which case it will go on a Q prefix and some operate crushing policies. The Q prefix cars that I have seen all have unique 18 digit VINs issued by DVLA and stamped by one source. For example, here in the NE, you would get the VIN from Eagle Star House in Gosforth and there is one garage which stamps the shell.

regards

NEIL