Cover and backcover feature Excel Saga, but there's no other content inside.
Backcover wasn't uploade upside down by mistake. It is in this position in the doujinshi and it's intentional, as it can be seen in page 4 of the gallery (numbered 2 in the book).
Whoever is looking for Excel Saga is going to be horribly disapointed and whoever is looking for Ranma 1/2 isn't even going to check this one based on the covers.
Was this just some horrible printing mistake or something?