That is the brand I am familiar with. It is masonite with an embossed and printed pattern that looks like tile. The installer must have used a black mastic that was common for that era.
You should be able to get it off ok, but it may tear up the drywall (or plaster) a bit and you will have the black adhesive to deal with. Try a 4" wallpaper razor scraper first, but you may have to use a solvent to get the rest off; the solvent would be flamable so be careful.
You could paint over that if you first prime with a shellac primer like KILZ or Zinsser's B-I-N.