Metal clad with precious metal (911110) involves a mechanically bonded layer of precious metal of meaningful thickness, whereas gold or silver plated (911120) refers to electroplated or similarly thin surface coatings on base metal. The distinction is one of bonding method and layer thickness; technical specifications or assay reports are typically needed to support the correct subheading.

Yes — parts for watch cases have their own subheading (911190) and are not classified with the finished cases. However, the material-based breakdown applies only to finished cases (911110–911180); parts of all materials consolidate into 911190 regardless of composition.