:Doug
You've got the spirit right. However, Siffert was nowhere near being a champion--I think he won only two races in F1, and Switzerland banned racing after the Lemans disaster of 1956, welll before Siffert's time.
And it's Ken Tyrrell who ran Stewarts' team, but it wouldn't surprise me if he handed the watch to his lovely wife Helen who was a fixture in the pits.
That said, I've booked a flight for switzerland and I'm wondering about bringing a shovel as checked luggage or just buying one there
best
Allen