So, having seen that you can edit any block models as of the latest snapshot, I though I would try editing the rail model to make it 3d. After several attempts, most of which involving just copy-pasting from another block, without any results (not giving me the misingno model, but still using the default rail model), I tried seeing if I could change any blocks. I started by changing the dragon_egg.json in meshes to coal_ore.json, and changing coal_ore.json in the main folder to use that instead of cube. When that didn't work, I tried changing dragon_egg back, and put that in instead. When that even didn't work, I tried erasing all of the models I currently had, dumping all of the models from the 14w10a.jar into my folder, and doing the same ("cube" into "dragon_egg" in coal_ore.json). Still nothing. I'm sure I'm running the latest snapshot, that I have my pack selected, that I've got the folder hierarchy right, and I have completely restarted the game every time. Nothing is working, and at this point I feel like it's a bug.