OH YES ! There are many,many recordings from the past that were not only poorly recorder, but also poorly transcribed and poorly produced. I have been able to clean up some of the poorly "produced" albums but it's only part of the picture.
I actually have found that MANY afficianodos of ROCK and ROLL and HEAVY METAL bands, etc. actually like the "distortion" associated with a large number of poorly recorded albums from the past. Even some of the newer albums or the so called RE-MASTERED recordings. aren't a hell lof a lot better.
You can clean up a little of the "grunge" with a first class DAC, but even with that it still remains a "GI-GO" situation. For some, the pain is worth it. I'M NOT ONE OF THEM !