As to whether or not it's worth using a computer to deal with the recordings, the original posting specifically asked about using a program to filter out unwanted noise. If your vinyl is perfect (doubtful!) you could record direct, but I'm too much of a perfectionist to put up with the results of that!

Cool Edit is all very well, but Sound Forge is much better.

Don't forget that a CD Audio track needs 2 seconds silence at the start to ensure compatibility with older CD players (and some cheaper new ones!). MP3 files don't need it; remember that an MP3 file is a compressed format, and some 'information' is lost during compression. Using an MP3 file to produce a CD Audio wave file is, therefore, not a bright idea! Wave to MP3 is the intended direction...

MIDI is being used to operate Fairground Organs, these days. It's so easy to operate a few electromagnetic valves from a MIDI player that the cardboard books can be preserved whilst still obtaining the exact same sound from the organs. It's not cost effective for pianolas, though... particularly as there are so many MIDI pianos around these days.