Admiral, multi car, if that matters.
Admiral were the insurers of Annette's Astra when a young girl crashed into the back of it, writing it off. Annette had been using the car up until when the assessor examined the car & his verdict of write off. Admiral then just happened to say that they don't insure write offs .... thanks for letting us know!
Perhaps what they should have said was, they don't insure them till they've had a VIC 
Been onto Admiral ... they want a "new" MOT and a VIC before even considering a quote .. original MOT is still valid and VIC only needed for a new V5C ... so neither needed legally .. just them being bloody awkward.
Justs hows what a bunch of rip-off merchants they all are ... Insurance is "supposed" to be about "risk" ... so how does driving a Cat C repaired car increase the "risk" of a further accident ?? .. answer .. it can't ... but we'll just increase the premiums by 180% ( yup ?87 to ?193) anyway ... 
Mmmmmno, I don't agree Nige tbh. If the first line of this thread is correct, that implies this is the first attempt to insure the car as a CatC....?
That being the case I would expect the insurer to want to examine the car structurally or whatever, to be cirtain that it has;
Been repaired
The repair is up to scratch
Its not been cut n shut.
The numbers still match up.
And then, once that been cirtified (by the Vic check)
It is up to Mot standard sine the accident.
Assuming I have the order of events correct, I've speed read most if it tbh.
No insurer will cover a cat c without inspection.
However if it's a historical cat c then the Vic check details should exist somewhere, no? Dvla? And then the original mot should stand.