Ok, I was not familiar with the name of the pattern... Satos Blueback Herring.
I have been given the fly a few times but have never tied it.
I will give it a try, more like a guess.
I would tie the head like a crease fly and bunch the bulk of the hairwing to fan up to give the hook the open gap that makes it ride nicely in the water. Keeping the build up of hair thin (not round) so you can then pinch the head, Most guys use Loco Foam - a sticky foam with foil , or a sticky foam like a gummy minnow. Dress as desired with color /Eye etc then use "hard as nails or Epoxy(my choice)
I included the 2 flies for reference, from the SWE library.
tight lines, I will try a few and post when finished....
cb