[davepl]

Shop manual, assembly manual, and the Haynes manual for that year all show it. At least that's where I looked. I have paper copies but they're online somewhere here.

From memory, the copper tube poking out of the signal assembly is indeed the horn contact has listed above. Then the plastic piece goes on with its copper or brass side facing the copper post. Plastic post goes into steering wheel. Steering wheel goes on, then washer, then nut. At least I think.

I've left out the little spring because you don't picture it, but there should be one.