Patek Philippe began production of Reference 3448 with the 27-460 Q calibre movement in 1962. Only 586 examples were made.
It is interesting to note that this particular watch was retailed by Tiffany & Co. The appearance of the glazed back and the way that the engraving of the inscription around the outer edge of the back suggests that this watch was done to special order at the owners request.
A similar watch is illustrated in Patek Philippe Wristwatches by Martin Huber & Alan Banbery, 2nd edition, p. 288.