They are not striker retainers but the securing pins for the plate that covers the top of the extension to the top lever that engages with the barrel top rib extension. You need to remove the plate to dismantle the top lever/ Scott Spindle joint.
And that tell's you what you need to know about the identity of the patentee: you will find that the top rib extension has a square hole in it and the toplever extension has a square section 'hook' like bite. This is a Scott patent that covers a few variants of this basic design.
I sold a gun with the same plate not so long back, the details can be viewed here. Patent details are the bottom of the page. It is a commonly seen patent in guns made by Scott of this era.
http://heritageguns.co.uk/Leech%2012%20SLE%203274/Leech%2012%20SLE%203274%20Details.htm
