Its authentic, but the mother of pearl dial appears fairly damaged/cracked at the minutes recording subdial. This model uses a module for the chronograph mechanism, with a 3 hour totalizer at 6 and a continuous 10 minute totalizer at 9.
It looks like a Shadow Flyback, so you're looking at sometime in the early 00's for age, which would lend to being so beat up. Cant speak to the bracelet.
If you're in the United States, contact Horological Services (https://horologicalservices.com/) They're the only Breitling Authorized Vintage service center in the US.
You can get a quote from them for what it would cost to repair and service the watch, which would be a complete overhaul.
The 1806 is fairly collectable and valuable, so it would be worth looking into getting it properly worked on. They provide estimates before doing work, and from the photo it looks like it is in overall good shape.
If you're intent on selling it, then obviously you'll be unlikely to increase the value much by having it serviced first.
Now if the crown came unscrewed from the stem, and it isnt broken, a qualified watchmaker should be able to reinstall it for you. If the stem is broken off in the crown its a different story and likely would require service.
Best of luck! They're cool watches and the oddball design/nature of them is what makes them unique and fun!