It could be an Edson
Pull-Pull conduit steering setup.
Check the top center link here and see if the parts
look familiar. I think there are some manuals
on the site also.
Check the accessories link for grease and oilers for the cable if the setup is Edson
Steering Hardware : Edson Marine Store
edit,... Looks like the pull-pull doesn't use a rod to arm attachment. So that's probably not it.
The Edson CDi
geared steering does use an rod straight to the rudder arm. But it uses a ring and pinion gear
in the top of the pedestal.
Check out these pdfs by boat type for Edson. I clicked on Coronado and Columbia
35 and neither show a setup like you describe.
So maybe it's not Edson after all. But who are the other manufacturers of wheel steering for sailboats?
I'm drawing a blank so far with Google