Thanks Jack, interesting. It wasnt the only pricy item in the common room. One day when I spilt some coffee I was politely reminded that the carpet "runners" which were strewn about the room were valued at £1500 each. My next job was down to earth with a bump in a tough comp. The Gainsborough would have been out of the staff room in a flash there and probably would have turned up at the local car boot!
Wonder if they ever found the other nameplate.