To find out the value for each textbox, click on the clock. The cuckoo will indicate the value. Fill in 0 for broken clocks. Do not fill in values for the faded out clocks yet.
Since the presentation in Las Vegas had two missing cuckoos*, 3 and 7, enter 3 in the first faded clock and 7 in the second faded clock.
You will get back the following coordinates: 51°30'02.61"N 0°07'28.66W. The coordinates correspond with the Big Ben in London. Therefore, the answer is "Big Ben."
To next puzzle: Pocket Watches.