Our house was built in 1970 and apparently was built to be sold immediately because I see some really sloppy work. In the bathroom, wallpaper has been applied to bare wallboard. I can see where the previous owners tried to tear it off and paint over it (it highlights those tears and gouges so nicely!). I've done a little research, and I'd like to spackle the flaws and cover with oil based primer before painting. Has anyone else tried this? Any advice for best results?