I've already spoke to my insurers. They will press his company for all fees, and my excess. I wont pay anything or claim on my own policy, Not worth paying out the excess or losing all those years of NCB.

The disc they're using feels near on smooth as the paintwork on a car so I'm guessing it'll only skim a very fine coat of paint. Then a polish of the 3M products should hopefully bring it back to when I not long bought the car. I only use microfibre cloths to wash the car anyway so theres no many swirls.