I have been correcting a few old mono records recently and a technique that I have found useful is to reduce the trace separation to zero to overlay the two channels. Dust clicks and grove damage are often on only one channel so it is quite easy to spot them as one colour spikes out from the trace.
It occurred to me whilst doing it a few other tools that might be helpful for this.
a) A DIFF trace (L - R) should be almost flat except where there was a click when a spike would occur.
b) The facility to copy from one track to another (L -> R or vice verse) using block markers thus overlaying a bad patch on one channel with the good one on the other. It may need blending in but shouldn't be far off.
What do people think - would these be of benefit?