To do the effect on the chest I used 3 of the channels for the texture.The first one was of the wood texture.Then in the second channel,the metal was added with a transparency map so the wood would still show through in the parts I wanted.And in the third channel I added the green moss(this also has a trans map applied so both the metal and wood textures show through).The technique is to basicly stack textures on top of one another using the diff channels and trans maps so they can all show through(note:a max of 4 diff textures can be applied this way on one object).On the chest I used 3 of the 4 channels.This way you can make very complex textures.I used a UV mapper to figure out the way the trans maps would be so they would allow the other parts to show through on the proper parts of the mesh.I hope that makes some sence to you.Maybe I'll add a demonstration to illustrate it better.