I thought that this could work, it crosses string leechs with tube flies. I furled a hook fo a string leech then doubled the furled part back back and nailknotted the loop (one drop of glue). Then its just a matter of tying the leeches on 1/2"-3/4" tubes. If wanted one could just use one furled section beacuse a hook could be changed and the fly. The pics will make sense of my nonsense. The second pic it just a invert of the first, gives a little better clarity.