No
One can purchase used Freightliner Century trucks from Auto Trader in Canada. The store offers both new and used trucks. If one is interested in used Freightliner Century trucks, there is a 2006 Freightliner model available at the store.
Different models. I have driven both models Cross Country. The major differences I can see are a different hood and different gauge layout. Some Older Columbias had a 2 piece rearview/convex mirror. Everything else appears to be pretty much the same, Unless there are specific options available to each model
5.25 inch speaker
Somewhere in the vicinity of 16,000 - 17,000
Never worked on the Century Class, but I am familiar with the similar Columbia... there should be a panel on the passenger side which can be popped out with a flat screwdriver.. that should expose the fuse panel. There might also be a panel by the driver's side door, just behind the seat, on the wall.
128 332 02
3.7lbs
This is going to be a very difficult question to answer, seeing as how the kingpin is part of the trailer, and not the power unit.
Code 128 351 03
Probably a bad power steering pump or bad power steering fluid.
That goes through the engine ECM, and you'll need to have it diagnosed that way.
Repair whatever's causing the fault. So long as the fault exists, the ABS light will remain on.