I just discovered there are two variations of one of the room keys that were listed from the Golden Nugget Casino in Atlantic City, NJ that people might not be aware of. It turns out the text above the magnetic stripe was printed in two sizes and normally only appeared on different cards but this particular card has both. On one it's 35mm long and on the other it's 48mm long.

Here's a scan of the common front and the two different backs.