Hey Karl.
Is it possible that I could send you a file to take a look at? I have a similar problem to what you were talking about earlier with the echo.
Battery died on my tascam dr-60D mkII during recording and I lost the whole audio track. I have created a new image of the SD card and was able to bring that into Audacity to find the lost audio. The track however has an embedded echo to the track and I am unable to correct that. I’m not sure if there is a simple fix or if the only way to fix it is to do what you mentioned above. I don’t think I can do that without messing it up even more. If there is a way you could fix that, it would be much appreciated!!
Thanks so much,
Adam