Interesting nymph. I would suggest that you build the thorax up thicker than the abdomen. It will give a truer profile to a mayfly or damselfly nymph. Build the thorax to almost twice the size of the abdomen. Wing case should be 1/3 to 2/5ths the abdomen length or shank length. Try that and see how they turn out. Tail is alittle long and legs are good. Legs should be shank length or slightly shorter. Do you have a proportions chart for nymphs. I can post one for you, if you like.