If you turn your wheel does it do so freely? Does the cable move in and out of the casing? The inside of my steering tube looked awful but clean-up nice with the WD and brush. For the brush I bought a 3/4" dia wire brush in the Plumbing Dept at Home Depot and had a 15" drill bit extension which I put in a drill and honed away. The stainless cable shaft clean-up with steel wool........The cable/sheath is one piece from helm to engine and come in different lengths which you need to match. They are stiff and not easy or fun to put in.
The absolute must of this project is the Steersman
http://www.steeringguard.com/html/whatitdoes.html