Yes, you really have to go back and watch it again!

Exactly, one really has to be alert and pay attention all the time -- but yes, you can see a blue Silverstone on Lauda's wrist on a scene where he is dressed up with his wife in some office or waiting for a meeting (can't quite recall) and the Carrera on Hunt's wrist at least in the last scene when he talks to Lauda at the hangar of his private jet company!

Cheers, Miguel