It was thought that most if not all the original black and white episodes were lost after the stories were remade in the 1970s in colour. With no further demand for the black and white films once the colour ones were made the episodes were deemed of no further value and lost in the mists of time. However in 2010, 41 years after they were last shown on TV, a stash of 24 16mm film cans was found in a shed containing many of the original episodes. These have now been preserved.
It is almost the same version as Ivor the Engine (1976). In the 1970s, this series was remade and the original scenes were colored.
The copyright to this series was originally given to Associated-Redifusion Ltd, who had commissioned Smallfilms to make the series. Associated-Redifusion regularly showed the original series on TV. In 1968, Associated-Redifusion had demised, so copyright was given back to Smallfilms, who went on to remake, using original episodes.