Replace that shitty combo square you got from Home Depot or Lowes and get this Hardened Steel combo square. Don't let that blue combo make you look like a cheap pussy, buy this.
I have checked all combo squares against my new Starrett, any that are for sale are still square today. For further tool clean up to improve performance: Clean inside the rule slide with a pick and oil the rule hold along with the spring, any nicks on the Steel Faces can be smoothed out with some sandpaper or a file.
All tools have only been cleaned and de-rusted to the point where the buyer can see the true condition and potential of the plane. They have not been tuned nor sharpened unless stated otherwise. (121)