Insurance for a 'CAT C' Bike

Do insurance companies care about this? If so do they load the
premium or expect any specific paperwork?

When I insured my Tuono, which I was told by the dealer had been a cat
'C' earlier in its life, I had to change insurers. This was /not/
because it was a cat 'C', but because it was an Aprilia.

My insurance has gone up a bit, but that's largely due to me now
having three road bikes, two of which are litre sports bikes, and
possibly the move to NU didn't help.

What are you buying now?

They never questioned or loaded me when I insured my Gixer, which was on
HPI as a Cat D when I bought it off Hog. They just treated it like every
other bike I've insured.

I rebuilt a cat D BMW but at that point didn't know i it was cat C or
D. Most inswearances didn't want to know if it was a cat C, nobody had
a problem with a cat D.

There's some info here:

Basically the Insurer /may/ require an Engineer's report to confirm the
repairs are of satisfactory quality.