Keep in mind that many guys will 'roll' the speedo after a full frame off - a similar thing that I don't understand. Like you said, everything is new/redone, but it still doesn't give you a license to start the speedo over again - just like it doesn't make sense to make claims about ultra low miles
BTW, it's a very, very small world out there! After completing my resto, I got my car appraised for the insurance process. I used Shaw appraisers for the task, never knowing that Cliff Ernst also uses him. So, when he came to look at my car he specifically wanted to see the speedo - and made a note that it was 'still' at 99k miles. Perplexed, I asked him why he was so concerned about the mileage on a fully restored car. His reply was that he had known of my car for the full time that Cliff had owned it, and knew the mileage should be 99k, and although it would be exceptionally easy to roll it over less a thou, he was pleased to see that it was not rolled over. He said it just speaks towards the approach taken on the resto, not hiding anything, keeping it 'real'. I thanked him for the compliment!