[1.8] Custom model bakery renders fine on held item but not in toolbar

Hi,

Continuing work on my bucket mod, I want to be able to switch models based on what the bucket contains, so I made a model bakery. All seems to work fine and the bucket in the player's hand changes based on the NBT fine. But the itemstack icon on the toolbar changes to the first registered render, even on a call to getModel(1) where 0 = water in the bucket and 1 = lava. Hope that makes sense... Am I missing something?

After further research, basing what I want to do off GreyGhost's Animate Tutorial is not the right way to do it. Back to drawing board.