If you ever decide to pursue this you should get in contact with me. I've got it part way started although its in C++. Currently using a dll made by someone else to read the MPQ files although it should hopefully be a simple modification to make StormLib(
http://www.zezula.net/en/mpq/download.html) work with what I need, however it seems to lack an actual license for use.
Got to the actual patching part and ran away in fear because its scary =/.