Try
https://www.thebikeinsurer.co.uk/ but make sure you don't enter your real details to get online quotes!
Use a different name, different reg number and slightly different postcode to find the best value quote - then phone the company and get an even better quote with your real details.
This is because insurance companies have to pay a hefty commission to comparison sites - even if you phone the company after getting an online quote, as your details are logged by the comparison site.
Car insurers won't cover you at all, and the motorcycle insurance companies don't like LT riders on a car licence - so good luck.
If you are with the RAC or AA, try phoning them first and they might point you in the right direction, but only if you are a member.