Slide a tungsten bead onto the hook. Add about ten wraps of lead wire, put a dab of Zap-a-Gap on the front and push the lead up into the back of the bead; a little more glue at the back of the lead locks it. Take a few thread wraps behind the lead and run the thread back to the end of the barb; trim the tag.
Tie in one fat gold goose biot flat on top at the rear as the first tail (this will later be pulled over the abdomen as a shell back).
Pair two more gold goose biots concave-sides-out, tie them in split (one each side, even length) over the first biot to form a split tail; keep them even.
Build up the abdomen with thread wraps, tapering it thick at the front (thorax end) down to thin at the tail for a stout stonefly profile.
Tie in a length of Flexi Floss at the back of the lead and stretch it as you wrap back to just ahead of the tails; trim. Tie in gold brassy Ultra Wire at the same point.
Wrap the Flexi Floss forward (clockwise) to form the abdomen up to the front of the lead/back of the thorax and tie off; counter-rib with the gold wire and tie off.
Fold the reserved gold goose biot forward over the top of the abdomen, keeping it square, and secure it at the front as a shell back.
Continue with the thorax and legs, then whip finish and cement.