I recently "restored" a rare recording of Teddy Wilson from the 70s. The recording was taken from a night at the King of France Tavern in Annapolis, MD. The recording had been archived to CD from a cassette tape at some point, so my source was actually the CD archive. The original recording was hardly favorable, so to get it to it's current state I used a combination of: RX Advanced, creative EQ and multiband compression. It was quite the chore, but I'm happy with the result considering the starting point of the material. You can purchase from iTunes, or Amazon.