Hi Keith,
There actually was a #7511 made back in June 1967, which would have been when Bing was producing a lot of DN noseriders. But, as you said, yours is a new Calvani-shaped nose rider.
We have only been doing the birth certificates for the vintage Bings, because Bing and I only have records for those boards. You might try contacting the Bing factory in Encinitas and see if they have any order information about your board.
Tom |