It's likely to need a new crown and pendant tube. I think you'll have to bite the bullet and send it back to B & R. Getting the old pendant tube out can be a challenge, getting hold of the correct parts is another challenge.
Screw-down crowns are trouble waiting to happen, if a watch is used regularly over a long period they usually end up wearing and giving problems. I`ve attempted to do repairs like this using generic parts and its a nightmare, never again. The quality of hat's available isn`t great.
The only screw-down crowns I`ve repaired successfully are Omega SMPs, I have the correct tool to get the pendant tube out, but nowadays I can`t get the parts so I don`t bother with them.
Unless some brave soul knows better and is prepared to take this job on, the watch has to go to B & R.