Confused on the Download Instruction
While I was helping my son rebuilding it, I was struggle with look for missing piece that don't exist. Until I finally realized there was a 2 diff instruction book with different piece but the outside of it look same. Even both are under same set number as you can see the different in those 2 image below.
This image come instruction book that use more techie lego piece to build support under it.
While other one instruction in here only use one large black train platform piece to support under it.
See it for yourself by go to http://service.lego.com/en-us/buildinginstructions/ and put in the "79104" search box and check out each link it provide and you will see the different.
So Double check the instruction the list of download link instruction
to prevent from get into confused again. ;-)