Nice ties! I haven't used a wire abdomen on my stonefly nymphs yet but will this weekend as I tie for next summer in Wyoming again. A suggestion you might try to incorporate that worked for me last year is to use two tungsten beads. (It kept the fly down with a lot of water in the streams.) One, black, at the head as normal and a second one in the thorax covered by dubbing. Stonefly nymphs tied this way have worked wonders for me in the Smokies in March and April. Last summer on the Yellowstone, below Tower, I fished it as the lead fly with a smaller unweighted nymph behind and caught lots of nice fish on both flies.