I am not sure if I exactly understand your question, but the watch looks good to me with that black leather strap.
I love Chronomtre Royales, congratulations on your watch.
Best Regards, Dan
I believe you may have meant "What strap...". I do not know of good straps for vintage Vacherons, as I have not begun to collect vintage yet. However, I do believe that some of our friends here in the Lounge may be able to offer some suggestions.