Sotheby?s, New York, December 10 2015

Sold for: $472,000

Some Patek Philippe owners, it seems, are just never satisfied. At least, that was certainly the case with the person who paid $670 for this white gold reference 3448 perpetual calendar moon phase watch back in 1967.
He lived with it (presumably happily) for almost 20 years before returning it to the manufacture for a service ? at which point he asked to be supplied with a new, yellow gold reference 3450 case; a new dial with appropriate, yellow gold baton markers; a set of yellow gold hands and a yellow gold winding crown and strap buckle. Furthermore, he ensured the whole lot was documented in Patek?s comprehensive archives, and even obtained ?permission? from the firm to be able to interchange the original movement between the two cases. The result is a watch that is thought to be unique and one (or two") which has come to be known among collectors by the soubriquet ?The Convertible?. In most cases, however, a watch being offered for sale with a spare set of parts to make it look different might not command much of a premium. What helped this watch achieve a believed record price was that a) it was a complicated Patek Philippe; b) that it was offered for sale with absolutely watertight documentation (including extensive evidence of regular servicing at the factory); c) that it was in great condition and d) that it was consigned to Sotheby?s by the family of the original owner.
In summary: Watches like this...