They would only work about a third of the time. That is why cover boards came out.
As far as setting them, you need your plow to be at the depth you are going to plow at. They set them so they are running 2/3 of the way in the ground. You usually have to have your coulter set correctly too for them to work at all. You usually set the coulter so that the front edge of it is cutting about 1/2 inch more than the plow bottom would cut. That way the coulter cuts a little relief so the sod/trash clears the plow bottom better. Those jointers will need to be shined just like your moldboards. That is the real hard part. Once they are scoured they will work but I have seen rusty ones that would never scour.