Apparently the original Rocket survives as well, and is located in the same museum (the National Railway Museum in York). The replica, shown above actually has a shorter stack to clear a bridge on the Museum's excursion track.

Two other replicas exist - apparently very difficult to photograph with yet no examples on RP. From WIKI: In 1923, Buster Keaton had a functioning replica built for the film, Our Hospitality. Two years later, the replica was used again in the Al St. John film, The Iron Mule, directed by Keaton's mentor, Roscoe "Fatty" Arbuckle. The subsequent whereabouts of the replica are unknown. There are, however, at least two other replicas of Rocket in the USA, both built by Robert Stephenson and Hawthorns in 1929, one is at the Henry Ford Museum in the Metro Detroit suburb of Dearborn, Michigan, the other at the Museum of Science and Industry, Chicago.