Homer52, some say don't paint, some say don't do this and dont' to that...and all are probably right to soem degree.
For me, I gave my rusty old springs a good blasting, painted them and put the poly liner between them. I didn't want "rust dust" weeping out between the springs and I figured the poly liner would help the springs work better since they showed some wear. I figure that will give the next owner something to do!!!!
Do what you think is necessary and to ge what you would like to have. Let us know how you do.