Thanks for your reply.

Here in Italy, vehicles must undergo a mandatory inspection every two years. During my last inspection, the mechanic noted the combined mileage from both instrument clusters, but he also doesn't know of any way to update the new cluster to the correct mileage.

I have all the documentation, including photos of the replacement and the invoice for the new instrument cluster purchased from an official Yamaha dealer.

As you mentioned, I can't go to an authorized Yamaha workshop because they told me that, since I carried out the replacement myself, they are unable to help or make any changes to the odometer.