I know on the older stuff that the rubber isolator for the bearing in the column has a staple in it, that supplied the ground for the horn.
I do not know if that was still done by the later seventies though?
i have scrapped several mid to late 70's newyorkers over the years, and kept the tilt-telescope columns.
all of those had a bare, "ribbon" type of ground running from the column at the mount bracket to the dash frame.
that "ribbon" is approximately 2 1/2" or so long, with eyelets at both ends. one eyelet is 5/16" to fit the column mount bolt, while the other is maybe 3/16" [?] to fit a #10[?] screw.
i don't know if this helps or not.
