Not sure - I thought it was based on risk. Anyway, she took all the details including value, garage, security etc. so I'm hoping she got it right. Will let you know if I find out otherwise.
UPDATE Just 'phoned CN to check. Apparently they have two insurers who underwrite modern bikes added to a classic bike policy - the policy is then converted to a Rider policy. One will allow modifications such as Termis, the other won't. Went through the requoting process to find out that the cost is now £289 not £63. Renewed with Ducati Insurance instead as its £30 cheaper.
If I'd been willing to put the standard cans back on then I could have added the 998 for the £63. Sorry, not worth it
[Edited on 28-5-2004 by Henners]