I have 2 Longines watches. I have contacted Longines and provided them with photos showing the watches, the mechanisms and serial numbers. They told me one of the watches was purchased in 1959, the other watch appears to be about the same time frame maybe a little bit older. Longines suggested I contact Sothebys and Christies, which I also did. Christies called me and I spoke with a Mr. Eric Wind. He verbally told me the value of each watch. The square faced watch approx. value is $2000 and the round faced watch approx. $800.

　　E-mail from Longines: We thank you for contacting us.

　　To carry out a search, we require the serial numbers (7 to 8 numerical digits) which are engraved on the movements. You will need to open the watches or have they opened by a watchmaker.

　　It would also help if you could provide some good and clear pictures of your watches (the inside of the case back and movement).

　　Waiting for your reply, we remain at your entire disposal for any additional information you may require.

　　Sincerely yours,

　　Aurlie Tonna

　　Brand Heritage

　　Compagnie des Montres Longines Francillon SA

　　CH-2610 Saint-Imier, Switzerland

　　Phone +41 32 942 51 99 - Fax +41 32 942 52 39

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　　Follow Up E-mail from Longines: Thank you for your message and the pictures provided.

　　Further to your request, we are pleased to provide the information contained in Longines' handwritten registers.

　　Originally, the serial number 10'664'400 identifies a Longines mechanical manually wound movement, caliber 23Z. It was invoiced on 22 October 1959 to the company Longines-Wittnauer, which was at that time our agent for the U.S.A.

　　The other parts of the watch were produced locally under license from Longines. Unfortunately, since the relevant archives are not in our possession, we are unable to provide any further information on your model.

　　We do not provide estimates of the current value of antique watches. Values very much depend on fluctuation in the antiques market, the law of supply and demand, the preservation and working order of the watch and many other factors dealt with by specialists. We suggest you contact antique dealers specializing in watches or auction houses such as Christies, Sothebys or Antiquorum.

　　We trust that we have responded satisfactorily to your request and remain at your entire disposal for any additional information.

　　Best regards,

　　Aurlie Tonna

　　Brand Heritage

　　Compagnie des Montres Longines Francillon SA

　　CH-2610 Saint-Imier, Switzerland

　　Phone +41 32 942 51 99 - Fax +41 32 942 52 39

　　Join us on Facebook, Twitter, YouTube