I realy hate new json system, and when i noticed that DummyCore can create items without jsons i instantly tried this. But it doesn work, item and block has standard black-purple cube texture.

Item class (Nothing interesting here): http://pastebin.com/BTjdZX6w
Item base class (That actually implents IOldItem): http://pastebin.com/UUb5LrLL
Registry class: http://pastebin.com/Jk48efBc
FML log: http://pastebin.com/8FJ7eyMx