I’ve branched development to a new git repo, so I have two repos for the code:
http://github.com/kisom/sfe_mp3 is the repo with my modifications to the default firmware, leaving most of SparkFun’s infrastructure in place.
http://github.com/brokenlcd/Custom-MP3-Board-Code is the repo I am writing my own code in; I am keeping MP3Dev.h but rewriting setup.h. This code is far from functional. It will be an interesting learning experience.