Barmy army on the beach

I am restoring and digitising a load of Super 8 films. They belonged to my father and grandparents. Rather than telecine them, which is copying the film frame by frame, I have opted to film them on the screen. This is much more like how I rememember watching the films the first time round. Sitting in my grandparents dining room, the projector sitting on the table and making the whole room hum.
This film is one of my father's. I can no longer remember which battle they are reenacting. I'm also not sure which beach they are on. It looks like somewhere near Birkenhead to me.