William,
here is my fly on a smaller 16 hook, but still a 2x-long.
The first point is to show again the effect of treating the wire brush as a rib by spacing the first wraps wide enough to let the silk underbody show through.
The second point is the exaggerated tapering, with nearly bare wire over the abdomen, and quickly increasing dubbing for the thorax, in addition to closer wraps.
This next photo shows my brush-making technique.
I had added a lip to the sloping drawing table to prevent paper from sliding to the floor. This lip also stops the Clark block when I am pulling on the wire clip to spin the wire. I don't slope the table any more now that I use if for tying, but the lip still turns out to be handy.
In this shot the spinning is only one-third-done. I like the rope to be much tighter.
You can see that I use very little dubbing, and that it tapers rapidly down to nearly nothing.
There is something about the layers of primrose silk, copper wire, and yellow-orange dubbing that suggests the glowing amber bodies of the mayflies we saw on the Willow. They looked like they were filled with golden honey.
Maybe I will get the water tank going now to reshoot this fly.