Rolex Day-Date 6511“President”

Ref. 6511

First generation Rolex Day-Date, pictured in what is considered the MKIII dial - first one said 'Superlative Chronometer by Official Test' and featured a depth rating, while the second featured the depth rating with the chronometer script as in the watch pictured. Released at Basel 1956, replaced by the 6611 in 1957.