I dredged up this old thread from a year ago while searching
for info on NX739 myself.

It’s mentioned that it was used for camerawork on The Dam Busters
– is this the mysterious “fifth” Lancaster sometimes mentioned on
the net involved with this film classic???

Jonathan Falconer’s excellent 2005 book makes no mention at all
of it which makes me wonder if its use in the film is just a myth???