Dreaded front sprocket nut issue

[darrsi]

I think someone on here has welded and also i someone tapped drilled and tapped a thread in the end of the shaft and did somthing.
Sorry not much help but perhaps you could help me as over the years on this forum I have not come across any 98 reg with the issue unless the sprocket has already been changed before. Do you know if the sprocket has been replaced before - how many miles has it done.

The sprocket has nothing to do with it, it's presumably that poxy ill fitting 9mm nut.