Wikipedia tells us about the later career of DP1:
In March 1961 DP1 was withdrawn after a serious powerplant failure; plans to test it in Canada fell through, and the locomotive was donated in 1963 to the Science Museum, South Kensington and placed on public display.
In October 1993, it was transferred to the National Railway Museum, York. It then moved to the National Railway Museum Shildon. In August 2012 it was loaned to The Ribble Steam Railway in Preston, Lancashire, which is barely a mile away from where it was originally built. It is envisaged that it will remain there until at least October 2015.I believe it is now back at Shildon. There is more about Vulcan Halt, where this footage was shot, on Disused Stations.