If you download the Spectrum Matcher from Cockos/Reaper and spend a little time learning how to use it you'll be able to a) take a match of a finished mastered reference track and have the plugin apply this to another piece of music .
It deals with EQ, levels and other things. It isn't specifically a mastering plugin and like any piece of kit it won't undo distortion within a piece BUT it's pretty cool AND FREE.
I've used it to "faux master" a track to suss out how reverb & EQ will react with limiting etc.
I still use an M.E. because I don't have the ears for the task and value to abstracted perspective an M.E. can bring.

Cheers
rayc
"What's so funny about peace, love & understanding?" - N.Lowe