Vacheron Constantin
Overseas Brown Dial
4500V/110A-B146
Tool-free interchangeable bracelet/strap system. The brown dial shifts between chocolate and cognac depending on light. The Maltese cross bezel motif is subtle enough that you have to know what you are looking at. Caliber 5100 with 60-hour power reserve.
Also in Haute Horlogerie & Independents