I came across this video the other day and as I was watching it I noticed that the pilot chose a 0 degree flap setting for takeoff. As I am not familiar with DC-4 procedures I thought it was probably normal (Like an A300). As the airplane begins the very looooong takeoff roll the camera pans away from the wing, and a few seconds later the aircraft rotates. Once airborne the camera pans back to the wing, and it shows that the flaps were extended probably just prior or during rotation.
The only thing I can think of is that these guys were not going to clear the end of the runway and added some flap at the last second just to do so. This would also explain the very shallow climb out. Tell me what you guys think.