A friend introduced me to a software called Mixmeister Fusion. He said it would be easy to find the key and keycode of tracks.
I bought it and in the past few months I have been recordings my records onto my hard drive and then get Fusion to check out the keys for each song.
The results were quite good. I have a database of 348 techno tracks at the moment that show bpm, key and keycode. Out of those tracks only three could not be detected by the software.
Then I saw a torrent for mixed in key so I thought I will give that a try to just compare the results. The same tracks came out completely different and the bpm of tracks in MIK 2.5 were totally wrong. That program went to the recycle bin quickly.