Can I just clear up things regarding no MOT invalidating your insurance.
Unless things have changed quite recently, then no MOT does NOT invalidate your insurance.
A friend borrowed my car a while ago and crashed it (that's what friends are for !!). My car was a write-off and the insurance company asked for all the documents, including the MOT. To my horror, the MOT had expired by a week or so (a genuine mistake) and I was panicking that no MOT would invalidate my insurance. All the insurance company did was to pay me less money for my car.
The value they originally put on my car (approx £1300) was dropped to around £1050 (I can't remember the exact amounts) as this was the amount they reckoned my car would be worth with no MOT.
I hope this helps clear things up :)