Ihave been meaning to try that technique on some dog collars, so that moves up on the to do list again. What speed reducer and from who, please? I am not far so might be just what I need.
Not sure of the video or the tool, but this is one of several that can help with lines
http://www.tandyleatherfactory.com/en-usd/home/department/tools/carving-stamping-accessories/3204-00.aspx
Craftool f916 is commonly used for grass. There is some good information on this in several al stohlman books like 'pictorial carving' available through Tandy