Thanks to McCreed for pointing me in the right direction. I have made the repair and the action is where I want it. I am a little out of place in relation to the E and G but this was the case previously on what was/is a cheap plastic nut. A valuable lesson learned, not quite as easy as is shown on YT and I will probably replace this nut with a brass one in due course. I have found that my nut files will cut a serious amount of material if I am not careful, as my old teachers used to say "could do better boy!"
sgtnutrep (1).JPG (60.4 KB)
sgtnutrep (2).JPG (56.0 KB)
sgtnutrep (3).JPG (44.6 KB)
First pic the deep cut A, 2nd pic baking soda and CA added, 3rd filed and strung