My research documented in Scanned image scratch removal with “ICE” shows that you need some pretty advanced inpainting techniques to get reasonable results. Even the dedicated code from vuescan does not do a good job here, only patch based algorithms lead to acceptable results so far IIRC. That’s probably not to far from the healing/cloning in retouch module, but the difference is that a manual source patch is selected there.
A sample image is available at the end of the thread above, and I’ll update the original post soon to include some more samples. Only dust and scratches, as this is detected by an infrared scan, unfortunately, fungus is not and requires manual work to recover.