Hi Joe...
Warren, interesting setup.... Do you mean attached to the spinnerbait hook
there are three trailer hooks, one after the other in a chain, with a #2
treble like the caboose bringing up the rear?

Exactly

What size of head and blades worked best with that many hooks?

This lure is designed to burned just under the surface, kind of the opposite
of "slow-rolling". Smallies will come up even from 25-30' depths to hit it.
3/4-1 oz is standard weight, with medium sized chartreuse painted blades.

Were all the regular trailer hooks turned up, down, or alternating?

Turned up generally

What kind of hook keeper worked best?

I never asked Kevin, but I think I use Strike King. They're about 2/0 I
think.

Which hooks were primarily responsible for your hookups... main shaft
hook?
Trailer hooks? Treble?

It varied, but on my glory day on Champlain more than half were caught on
the treble, which was trailing the back of the skirt by several inches. The
bait is designed to catch the bass that takea half-hearted swipe at the
bait.

Warren