Huh? :shrug: Why would replacing the instrument cluster be illegal? Mileage? The mileage can be documented by the owner. Also, there's a company in California that can set mileage. This one has around 10k miles.
its illegal if you don't document the mileage because there is no way after the original cluster is removed to find out the miles without documentation, which would be probably the reason for most of the generated interest in your item for sale. People wanting to engage themselves in illegal activities. It's smart but ill advised. Rolling with lower miles and switching back later on can save someone a lot of money.