I have now checked this mini series completetly, but it’s not the movie with the stairs I hoped for. (Or I have missed that scene but that is very unlikely). The stairs are very similar.
In fact only one or 2 very brief scenes of interest. One teen boy swimming shirtless in tighty whiteys (front view only, starting at 44 minutes on disc 3). And 6 yo Usepping peeing in his pants. Some scenes at school in school uniforms. Stripes on the sleeves but no sailor suits. Even no interesting scenes of men in uniforms. 1 hour is set 6 years earlier.
Image quality is partly a bit poor (grainy, running stripes, maybe although perhaps remastered) but disc 3 is OK.
So the search continues.