Photo 53, the adjusting tool shown isn't for a No5 rifle but a Sterling SMG. It is the TOOL, adjusting, foresight No5 but it is not for the rifle. It is the No5 TOOL. I think that the TOOL, adjusting foresight No4 is for the No5 rifle.

Photo 57. Those backsights were done on the cheap for the L81 A1 Cadet target rifle. It is said that P-H made them so dire to the point of sheer crap so that the competitive school Cadet Forces would be obliged to buy P-H sights to get onto the target. But, alas, not just your old P-H Mauser sight that you might have handy as it fouled the bolt when you lifted the handle