About this matriculation number there were a wide discussion because: a) According the Eng. Mario Paci, Panerai Sistemi, Florence (Now Calzoni Group in Bologna), the Luminor no. 900 doesn't exist in their production's archives at the time (1993-1997), so has never been produced into the factory and however its signature (AQU) in the certificate of conformity is a fake; b) According the Officine Panerai-Richemont, Milan, this watch has been made with all its genuine parts.
It's an hybrid watch? That is has been made with all its genuine parts, but with a wrong matriculation number? (Piero Lapiana, Club Panerai, Italy).
With the pubblication, in the 2004, of the D. Zei's book about the history of the Officine Panerai, Florence, we shall have the definitive solution... However, see also the interesting photos and documents, part 1 (Jan. 2003) and the final reply, part 2 (Sept. 2003) of Mr. A. Bonati, CEO of Panerai that writes the world -the end- about this Luminor, ed. 1993, matr. 900. For more info, about this watch, contact Bijan Javid, Usa and Bernardo Beltran, Spain.
See also the Certificate no. 00346 with the two photos of the watch.