ZL_IS is from CS.java and is a Zero Length ItemStack Array.
And the Recipes are at the end of the very long Line that is used to initialize the Cupboards.
Yep all Inventory Sizes are hardcoded and not dynamic at all. I was lazy at the time…
Edit: Oh you mean for the Metal Chest of the same type? aRegistry.getItem(i+whatever) should be the one you look for