I estimate the date to be about 1860 to 1870. The dial is held by screws from the front which turned out to be a bad way to do this as you can see by the damage done by poor screw driver technique. That and the thirteen jewel nomencalture pretty well dates the watch.
The winding is obvious. That is why there is an arrow, more on that later in this post. The setting square is marked "Hands" and means that you move the hands directly with the key in that square.
Detached is "detached Lever" a feature. The center square is to set the watch. The history of the lever escapement is long and complex and counter intuitive if you are just starting learn about it. Up the 1850's most watches had escapements that kept the balance in mechanical contact with the drive train. The most descriptive name is "Friction rest". The lever had is a detached escapement in that except when it is acting, it stays detached from the balance wheel, which is a very good thing.
The early lever escapement had some other problems which led to brief rise of a "rack lever" which solved those problems but lost the detached feature. A detached lever that actually worked well was a significant feature in the English market. English watches used a more complex power drive called a fusee and chain. Again, long history and lost of technical detail. The salient point is that fusee driven watches wound the other way, so that arrow was fairly useful for English owners.
Vacheron always made good watches and while this is very up market its bit below the top grade since it does not have temperature compensation on the balance.
On a closer look, I'd date this watch to the 1850's, although 1860's are still reasonable.
I should have checked the serial number, which I just did. It puts the date at about 1854. We don't do values but a good overhaul would cost in the range of the value of the watch and a more if it has serious problems. If you want to wear it or use it, and really like it then do it. If I had a family heirloom like that I'd get it done but it is not a financially beneficial thing to do.
The dial damage is real issue and there are many differing views on how and whether to try to restore it. Unless you know of someone who can do this well I would leave it alone. A good job would be comparable to the value of the watch. The common view is that dials like this are not restorable but there are ways to do it.