Spend hours decoding by hand, trying all software possible, finally get the right application, and win.
After many different pieces of software, the program "mreader" from mreader.free.fr was found. The wav file had to be converted to an 8-bit wav for it to be recognized by the program, and with the default ISO2 setting, the data was returned as: ;31337157?. That was the key, minus the ';' and '?'. The ';' and '?' are the beginning and ending sentinel characters for the data stored on a magnetic card.
Various things we tried that failed: