After you park and shut off the engine, you put the the gear into reverse and it locks the steering column. Beginning in '71 or '72, Chrysler stick cars incorporated a much simpler column lock configuration inside the column which did away with the external interlock rods.
The bell bracket is incorrect for a 70 A body in that photo. It should be a flat "L" shape with a flat "hook" at the end and mounts to the machined surface with the vertical/parallel threaded holes. The frame bracket is correct part wise for a 70 A body but it is backwards. Also, in the photo, the cross shaft appears to be connected to the lower bolt mounting hole. The cross shaft needs to connect through a bushing in the upper hole.
The lockout setup was missing on my 70 Duster when I bought it 25 years ago. I scoped out a local original owner 70 to see what an untouched factory setup looked like. Never gathered all the pieces though. The brackets are fairly easy to find as they are usually left behind, mounted on the bell and the frames. It's the rods that are harder to scrounge since those are what was pitched when they were new. Overall, not a hugely critical setup to have unless you crave a locking steering column or it's going to be a points car.
Tony is a good guy in the hobby. He'll make things right with you.:thumbup: