navitimersuzy wrote:
If you can help me in any way, I would be very grateful.
No doubt a rare timepiece, and lovely that it is accompanied by the boxes, papers and accessories. Please note that everything I say below is predicated on the assumption that your friend wishes to sell this watch. If they wish to keep it, my advice would be different.
The problem in establishing value is that there are none of these currently up for sale, so this can only be done by proxy and then adding or subtracting based on comparing characteristics of what you find. For example, if you go to Chrono24 and search on yellow gold, white gold and platinum Navitimers in the year range 1990 to 1999 you will currently see eight watches worthy of comparison ranging in value from €7.5K to €40K. This is a wide range, but I would suggest in a fair marketplace this watch would be at the higher end of that range.
Now before any excitement builds, there is more to determining value than simple comparison. You also need to find a sales channel that you are comfortable with and to find a genuine buyer. Sometimes this can be as simple as listing it on Chrono24 or eBay at cost a little higher than you "feel" it is worth and then negotiating down to an agreeable price...or it could be more comfortable to find a reputable dealer to sell it to, or through them on consignment. Online resources like Chrono24 and eBay can be a bit of a gamble with regards to safety, while dealers will always take a quite sizeable cut of the value. Please consider the options carefully and temper expectations.
Finally, the general consensus with selling watches is to sell them as they are, as you will not recoup the costs of a service. However, in this case I would go to the relatively small expense of finding a reputable independent watchmaker (that is, do not send it to Breitling) to re-attach the chronograph hand so the watch looks whole again. Living in Europe you are likely to be spoilt for choice as to who you can approach to undertake this small task, and someone here may even be able to help with a recommendation.