You are confusing the two different pairs of screws. The ones on the action FLATS are to do with retaining the cocking rods mentioned in the Perkes patent. The two screws on top of the fences are a Scott patent concerned with 3rd bite top rib extensions.
The spat between Perkes and WR was only about the ejector part of the patent, not the cocking rods and anyway Perkes prevailed even though it bankrupted him. As a result he sold the patent, cocking system, ejector et al to Scott who were then free to work it.