IWC Schaffhausen’s latest addition to the Portugieser is a technical and material feat. The new Portugieser Tourbillon Retrograde Chronograph (Ref. IW394009), limited to just 100 pieces and priced at $145,000, combines three high complications—a flying minute tourbillon, a retrograde date display, and a flyback chronograph. Additionally, the watch boasts a  newly executed 43.5 mm…