After some recent disk trouble I got to thinking, what would a developer have used back in the day to resolve disk issues with the +3...
I reasoned there had to be software available to do this. And sure enough there was..
I didn't expect it to be quite so well written though.
https://spectrumcomputing.co.uk/index.p ... 6&id=11653
Very nice! Well documented to (however there appears to be no scan of the orignal docs, just a type in is left.)