I am not sure if it has any DC 4s, but I bought the DVD "Look at Life in the 1960s, Civil Aviation" fromvideo125.co.uk
It has 3 Look at Life films, including "City of the Air" which has footage of Heathrow, Gatwick and Stansted.
It was probably filmed after DC4s were retired, but there may be a shot of one in it somewhere. There is plenty of excellent footage of planes, airports, and vehicles as they were back then, brings back so many memories and highly recommended!