I am renting a victorian flat in San Francisco and with rents here hate to move and am trying to make this place more livable. Years ago some one hung wood paneling in the living room and I am trying to take it down to repaint. Behind the paneling are plaster walls and with the adhesive of the paneling I am getting down to the bare plaster. There seems to be a paper sheeting that was applied after the plaster. Do I need to replace this? Can I just seal it with a primer?