The ship, the title and the poster

The real ship was HMS Leamington (G19), ex-USS Twiggs (DD-127). She belonged to the Soviet Navy for a while.

In my opinion the British original title is much better than the American one, which is obvious and pretentious, like so many other similar titles. It loses completely the reference and the connotation: To look a Gift-horse in the mouth, do not unappreciatively question a gift or handout too closely, to criticise or refuse to take something that has been offered to you, etc, so the title is understood by anyone who has seen the film or knows what it's about.

The British poster is also better:
https://upload.wikimedia.org/wikipedia/en/3/3f/Gift_Horse_VideoCover.jpeg