Variants of a mold are catalogued separately, so each one has its own sets and minifigs. Check these too if something you expect is missing here.

• 820 Baseplate Raised 8 x 18 with Garage Floor Plate (Old style) this part is a mold of it
• 820b Garage Door 1 x 3 x 5 Automatic with One Octagon Stud and One Round Stud (Old style) Pair of this part
• 821 Garage Door Frame (Old style) - Studs Pair of this part