IWC Old Inter Cal.8531
Symptoms: Regular maintenance
Repair contents: Overhaul and case cleaning
Repair cost: 27,500 yen
I took it apart. It's a vintage IWC model, the Old Inter. It's said to be a great watch with a Pellaton-type automatic winding unit, but there are significant individual differences. This one is in good condition, with no particularly bad wear or tear.
Assemble. Calibers starting with 85, such as the 8531, come in a variety of models depending on the year. There are parts that are interchangeable and parts that look the same but cannot be used interchangeably. Parts are available to a certain extent, but most are imported from overseas (Germany, Switzerland, etc.), so they tend to be expensive.
The back side. The date advance mechanism is simple, but depending on the caliber number, some can advance the date by going back and forth around midnight, while others cannot.
Attach the dial and hands. The 18-karat gold case gives it a luxurious look. If the hands are cloudy, remove the stains with chemicals. If they are discolored or corroded, they cannot be treated, so they are installed as is. In the photo, the luster has been restored with chemical treatment.
An automatic winding unit was installed and the case was put back in. Even if it is a fine watch, parts will wear out if not maintained, so we recommend regular maintenance.
We will also introduce repair services. We hope you will find the information useful, such as prices.