Gear box shaft replacement

[Tiberius Onklevaart]

Nut came off my old bike. It wore the end of the output shaft quite a bit. I got a dremel type tool with the thinnest wheel available and steadily and carefully made an opening for the thread. If you are mega careful it is saveable. there won't be much thread but it will be enough. Or rather, should be, as long as it ain't ground too much away already tho