Thanks for all the advice and personal experiences!
Decided to name and shame, the insurers are Dial Direct, who have been good to be fair with trying to get answers but ultimately it's the underwriters, Covea who enforced the increase and state that the reason for said increase is due to IF the car is modified, they have to cover the additional repairs if there is an accident??
The car isn't modified, I have had type 1 for 12 years, I've never had my licence questioned or revoked at renewal, don't have any issues that warrant amputations or modifications.
I quoted the Equality Act and was told 'nothing to do with type 1, it's purely if the car is modified', advised it is blatant discrimination as they are penalising people on the basis that SOME restricted licences relate to cars needing to be modified!
So... I have spoken to EASS and am now lodging a formal complaint.
Not one usually to make a fuss but it annoys me that I only discovered this due to an error in my paperwork requiring an amendment, so how many other people have been charged extra unknowingly!
I have now changed over to another insurer who have not charged any additional premium who the unfortunate 'pleasure' of having Type 1