Some insurance companies insist that the car is re-MOTd after Cat C repairs before they will reinstate cover. Mine tried to Cat C my 4be, complete with a VIC check and new MOT. I had it re-assessed at my insistence and they removed the Cat C and VIC markers as well. As I had already started repairing the car after buying back the salvage, they settled for a £1300 in lieu payment to cover my repair costs. The first assessor valued the car at £720, the second one said £4000. They will always try to get away with the minimum settlement they can get away with, works for them most of the time because people don't tend to argue.