To open or not to open
Some would say that not to open a watch is akin to appraising a car without checking the engine. So how should you proceed? This all depends on the type of watch you’re appraising, the supporting paperwork, and your level of expertise. For example, if your client purchased a brand new Patek Philippe Calatrava from Tiffany & Co., and submits it to you complete with the box, papers, and receipt, it would be safe to assume the movement and parts are original. The serial, calibre, and reference numbers are provided in the paperwork and can be cross-referenced. However, without proper papers, it is possible the same watch may have been purchased on eBay. Here, the only course of action is to open the case back to obtain the serial number and calibre number (which is located on the movement), along with the reference number (found on the inner case back with Patek Philippe) before you can conduct the proper research.
It’s perfectly acceptable to work within your limitations and collaborate with a local watchmaker to have the case opened professionally. Once that’s done, photograph the movement and inner case back, write down the details, and have the watchmaker close up the case. Remember to pass the watchmaker’s fees on to your client or include it with your appraisal fee.
