Nor have we worked out what these two controls are. Each knob can turn three times, each has two opposing scales. It feels as if it's some sort of coarse setting for the sights, but we have not been able to set them in such a way that the sights exactly match the barrel.
Just for completeness, this is a closeup of the actual sights. We know that the items that look like boxes are the night sights.
As I said earlier, any information will be gratefully received ! Many thanks in anticipation !!