50 quid is way too much for a NATO strap no matter how well made you think it is. If you match the color right, you won't even notice the difference personally if you use a generic NATO strap from your favorite supplier.
I see strap insanity has shown up at Rolex...
PS:It's really a nice NATO strap though on that Rolex. It looks much better than James Bond's....

Oh abang James, your strap is several sizes too small for your Sub!
(image from
Thunderball)