You've hit the nail square on the head there Lorry.
It's Health and Safety gone crazy, masterminded by people who haven't got a clue.
If you read the responses to the consultation document, the police are concerned with spotting ringers and getting them off the road.
But here's a thought.
You could easily go out and buy a crashed 2 year old Mondeo, take running gear and interior out of it, bolt it all into a new shell and put it back on the road.
You take it to the MOT station and the guy looks at it, tests it and, because it is not modified, it goes back on sale no questions asked...... No SVA.
Of course that doesn't mean it's a dangerous wreck does it?it's safe because it's not been 'modified'
Or you could take a completely rebuilt 1960 Zodiac, with a full cage, race derived suspension, race derived brakes, built by 'say' Andy Robinson. (For those who don't know, one of the top chassis and racecar builders in the UK) to the same station.
It would be reported to VOSA as modified, subject to SVA and would fail.
Of course it's not safe is it, because it doesn't have reversing lights, foglamps and the switchgear has the wrong radius..