Monarch Mirrored Wardrobe manufactured in 1983.

Thanks for posting. Your roller looks like it could be either the 23-042 (round) or 23-074 (square) Mirrored Door Roller, depending on the shape of the "spine". I can't quite tell what that might be from these photos, so you'll need to remove the roller to confirm and then compare the dimensions.

Please note that the bracket that connects the roller to the door is obsolete, so it must be reused. Be sure not to throw it out!