hiya Rubi
the only thing I know to say, is that I am a serious but amateur digital audio restoration specialist, specializing in repairing the defective audio from phonographic discs and tapes. I have never been able to successfully market my skills to anybody. I have had very few takers, one-off jobs paying me pocket money. I would very much like to do this professionally, but it seems out of my reach. part of my problem is that most record lovers also seem to LOVE the surface noise [which they generally call "ambience"] of their discs no matter how objectively noisy they are. IMHO a lot of record collectors are a bit strange.