After some overzealous brake alignment efforts, the post-mount thread became stripped and the bolt retained only with Loctite. I baulked at the cost of a replacement fork so I ordered M6 thread insert repair gear.
Yeah, that thread is gone. I used the drill and vacuumed out the old stuff.
Inserting the new thread. I bought longer ones as I feared the ones in the kit would be too short.
Oh dear. The tool gets stuck and there's thread left over. I cut it off with cable cutters.
The thread insert guide tool is a bit mangled. Perhaps I will measure the depth of the drill as well as the depth of the tap before driving a thread insert next time.
Otherwise it seems to be a solid repair at around $15 (with my own labour but less wastage) instead of $100.