I respect your attempts to do it right, but do you really think anyone will own your vehicle after you? I think potential buyers are the only ones that will care about something like that.
I can only hope that my truck makes it to 293k miles, and if it does, I plan to keep it until it is absolutely worthless to someone other than myself. If I was in your shoes I would replace the cluster, call it a day, and keep track of the ACTUAL mileage myself...but I don't plan to sell my truck...unless I sell it to a wrecker or the insurance company pays me out for it...
Just food for thought.