Here's an original genuine Minolta XG XG1 XG7 XG9 XG-M Back Door Door. It is used but in great shape, may show slight wear 

 A very clean  door.

The door is easy to replace, there is a latch on the doorpost, just pull the latch with your nail, the old door would come off, same way to mount the new one. It only takes 20 seconds.