The present lot bears the cancelled reference number 6565 in the case back. References 6565 and 6566 are identical with the exception of the bezel; on reference 6565 it is engine-turned with hour divisions; the bezel of reference 6566 has the addition of polished arches between the hour divisions. This type of bezel was called the ?guilloché fantaisie? in period advertising. The calibre 1030 was produced between 1950 and 1957 and continued to be found in watches for some years later. Reference 6566 was produced in stainless steel Rolesor and gold. This watch is illustrated in ?Rolex Collecting Wristwatches? by Osvaldo Patrizzi 2001 Edition p. 192.