Enfield rifle muskets, rifles, carbines and musketoons were used in the war, and imported by the hundreds of thousands (mostly rifle muskets) by both combatants.
For the most part, the Union stopped importing Enfields from England by mid 1863, as their production of Springfields by the government and dozens of U.S. contractors was sufficient by that time to no longer need imported weapons.
The Confederates continued to import Enfields through mid to late 1863, and possibly some limited quantities beyond that point, but lack of funds became an increasingly serious problem to the Confeds by this time. While blockade runners did continue to arrive at some southern ports later in the war (including 1864,'65) their numbers were much less than in earlier years due to fewer Southern ports available, less funds available and higher inflation, and a somewhat more effective Union blockade.
Therefore, while one cannot definitely rule out its possible use in the American Civil War, I would think it rather unlikely. The English exported Enfields to many additional countries beyond the U.S. and C.S. during this time period.
By the way, I am not sure what you mean by a "VRB" Enfield? Some Enfields had a "VR" below a crown on the lockplate (for Victoria Regina). But I'm not familiar with the term VRB.