After a bit of experimentation and trial and error managed my first attempt at a prawn fly. Based on a JAM fly but cant really call it one as I dont know the exact steps.
http://i1057.photobucket.com/albums/...pstv03vyc1.jpg
http://i1057.photobucket.com/albums/...ps9mtkjofd.jpg
Passed the basin test and rights itself.
http://i1057.photobucket.com/albums/...ps11oyumeh.jpg
any suggestions would be appreciated.