I mentioned this earlier in this thread.
If this is a real 76 key Tyros 5 it looks like it is about the same width as the 61 key Tyros 5!
Open up a picture of a T4 and compare the two.
Look at the USB storage device slot on the 76 key Tyros and compare it to the USB storage device slot on the Tyros 4. That alone saves about six keys. Now look at the left side of the keyboard. the wheels are much closer to the edge on the 76 T5 than the T4.