So, I'm in search of some pics of an extension by Robbie McIntosh. My teacher has an extension done by him on his Panormo and as he describes it, "It has little leather fret thingies on each of the notes." I think it has a gate on the D and E, but I'm curious about the "leather fret thingies." If my conception of the design is right, does pushing the string against leather as opposed to the ebony have a substantial effect on the sound?