According to the Archives of IWC the present watch was sold in October 1977 to Frankfurt. It is number 22 of a limited series of 100 examples of reference 5500 in 18K gold made in the same year.

The movement is beautifully hand-engraved and signed in script. The moon phase disk is made of 18K gold, depicting the moon against a starry sky of goldstone. Shown with great accuracy, the moon phase requires adjustment only every three years.

The following text regarding the story of reference 5500 was kindly supplied by IWC:

“Today, IWC’s watchmakers are proud of the fact that they are able to integrate all the complications mentioned in watches from Schaffhausen. The history of complicated watches from IWC is a very special one. Before the advent of the quartz watch, IWC had specialized in precise, high-quality watches without any complicated modules.

As interest in mechanical watches dwindled in the 1970s, IWC decided to focus on a small group of watch devotees and customers who had not abandoned their love of mechanical watches. In effect, IWC launched a counter-revolution against the quartz revolution that had taken place in the watch industry. Most manufacturers in the watch industry – even in the luxury sector – had either neglected and forgotten the art of watchmaking or had been forced into receivership. Not IWC. Bucking the trend, the company’s Executive Board charged watchmakers, Kurt Klaus among them, with the development of several small series of complicated pocket watches. It was a bold step, and one from which IWC was to reap enormous benefit in the long term.

The first fruit of such efforts was the Reference 5500, a Lépine open-face pocket watch with calendar and moon phase. Unveiled at the 1977 Swiss Watch Show in Basel, it was limited to 100 pieces and sold out in a trice to lovers of classic, mechanical timepieces. In the following years, Kurt Klaus devoted himself to other haute horlogerie projects. The complications were featured not only in pocket watches but also in wristwatches. The designs and mechanisms consolidated IWC’s reputation as an manufacturer of high-quality, complicated watch movements.”