Item rendering based on NBT [1.12.2]

I'm trying to create a tool which could safely convert any tile entities into a "tile box" and that part works just fine. I stored the block, tile entity data and the block states in that tile box nbt.

Now the problem I'm currently having is trying to render the tile box based of the block if there was a block in the NBT.

For example, I have a chest with some items in it and I use my tool and shift + right-clicked the chest with it and it drop my tile box with the nbt tag. Also, I know I needed two different render classes for both the item's entity (when thrown into the world) and when it is in my inventory.

I have tried creating my own render class and stuck on how I would register the class for my specific `ModItems.TILE_BOX`.

Any ideas on how would I implement these?