Need feedback: MONSTER MAKER Parts Menu

For the upcoming iOS7 optimized version of http://tinyurl.com/monstermaker I'm looking at simplifying the PARTS palette. Right now I have five icons -- eyes, mouths, legs, bodies, accessories -- but the app has grown to more than 500 parts, and many don't fit neatly into any of those categories. Is a drop down menu the best way to go? It's not as pretty, but would offer a lot of flexibility. Are there better options I'm not seeing?