After seeing quite a few mods that have 20+ classes for armor, basically a whole new class for every single piece of armor, I decided it was time to write a tutorial on how to code in an Object-Oriented Programming-friendly fashion, and put together this demo armor mod.
I have used this exact code to add dozens of new armors to the game, using several custom and vanilla armor materials, all using the exact same ItemCustomArmor class. One class, dozens of armor sets. There are lots of comments in the code; please read them.
As a bonus, I threw in a mini-tutorial on how to effectively and efficiently add armors with new models, and although the model I had on hand does have some flaws that you can see in game, the basic premise of adding models to a map is still extremely useful. If your models are otherwise working correctly, you can use the method I show to streamline their addition into the game, rather than using lots of clunky special cases.
Anyway, I hope this little example proves useful, and hope to see mods with far fewer classes in the future :P