Not exactly “seen” such rifle disassembled, but perhaps the following… Now ‘flying’ from long ago memory. Viewed a 54 Standard model Lyman receiver sight equipped & appearing stock. Fitted with aftermarket trigger, perhaps a Timney (?). The bolt stop function ‘described’ as adaption by drilling through one of the factory receiver sight screw holes and utilizing a longer, hardened screw. Recall an “improved price”. To me “jerry-rigged” & something of a pity!
I’d be particularly interested in knowing how your bolt-stop function was achieved. Hopefully not by such method.
Sounding the stock you describe likely not factory “Supergrade”. Internet exemplars of such originals are available. It does potentially sound quite nice! Photos would likely also be quite nice to view! 🙂
Personal opinion, the 54 in advanced decades, virtues of originality more often trumps even handsome/clever “improvements”. h
Hope this is perhaps some assist…
Just my take