Fixing a Chas. Osborne BLNE. Havent seen a safety indicator dovetailed into a tang before. Was this common? Any one happen to have one? Mine is missing.

Also, is the tang screw a fairly standard part for A&D boxlocks? If so, anyone have a spare screw for this purpose? I could make one, but would prefer not to.

Pics here: https://drive.google.com/drive/folders/11N5kFl4P1knIsxynSj9wlK-5fedUr4pa

Thanks!