Similar issues here, just called to suspend my insurance and get a quote on an e46 M3 - “nope, we don’t insure cars older than 04” - well the car I had my policy on was 03 - “yea but that’s cause you had a policy with us” - eh... I still have a policy with you! - “we’ll have to refer it on then” - refer away...

If the car is NCT’d then it’s deemed roadworthy and that should be the end of it...