The present reference 6536 is one of the rarest Submariner models ever produced, featuring the very first depth rating used by Rolex, the red printed "100/330". This style is known to exist on an exceedingly small series of this reference only, on all later models the more common 100m=330ft printed in white was used.
The theory that Submariners of this series are exceedingly rare is further highlighted by the fact that the present reference 6536 was originally destined to be a 6538. Both original reference numbers, featured between the lugs and inside the case back, were corrected at the time of manufacture at the Rolex workshops. Whereas the last digit of "6538" between the lugs was crossed out and replaced by a "6", the entire stamped reference number "6538" inside the case back was triple crossed out and a new reference number, "6536", was inscribed in a new position. Watches like the present example beautifully show in what artisan manner Rolex produced the earliest Submariner divers watches.
This watch is self-explanatory for the reasons and fascination evoked by collecting historic Rolex sports watches.