2nd time today I seen people lose keys, man at Snetterton(market) lost his today as well, for a ultra rare toyota 800s.
Not much help to you I know but for tohers I always put a small dog tag on my keys, not the metal sort but the cylindrical plastic waterproof sort, with the little roll of paper inside with contact details in it, nb don't put your own contact but that of a friend neighbour etc, otherwise they come and steal your car!!
Dog tag thing only 50p, could save a headache!!
tabetha