Complex sentence: U.S. Games Systems, Inc. has a copyright claim on their updated version of the deck published in 1971, but this only covers new material added to the pre-existing work (e.g. designs on the card backs and the box).
Split into simpler sentences: U.S. Games Systems, Inc. has a copyright claim on an updated version of the deck published in 1971. This copyright, however, only covers new material added to the preexisting work (for example, designs on the card backs and the box).