A bit tarnished but may be able to clean up. I've got some Brasso here (not for giving away) which you could try before taking. I'd use the Brasso myself but am a little sensitive to it.
You'll need to check this is the right size for your letterbox - dimensions in photo.
Victorian Brass Letter Plate (Pilton EH4)
This offer has been gifted to someone and is no longer available.