Nice I've been planning to do something similiar, except with every song that has been played live over the years.
One thing though converting MP3 back to WAV is pointless, as information is lost when it was converted to MP3, and this information can not be recovered from an MP3 file. If you do a frequency analysis of the WAV files you have created you will see the difference between an MP3 source and a proper lossless file.
Here is a frequency and spectral analysis of a lossless file.
Here is the same file converted to 192K MP3 then converted back to WAV
As you can see there is quite a difference.