When the museum purchased De Luxe s/n 5051 April 2010, it had a bridge with s/n 9579 blind stamped on the underside of the bridgefoot. The bridge originally must have been on De Luxe s/n 9579, which is one number higher than one of the two Super De Luxes we know of: Super De Luxe s/n 9578.
One wonders whether the original bridge of the De Luxe s/n 5051 is still around somewhere. If you have any information on the matter, please contact us about it and we most certainly will get back to you.