A real shame. I remember meeting Jock at The Three Frogs, many years ago now - he was a genuinely decent, enthusiastic and interesting individual - knowledgable but never derogatory of those who had less knowledge than he.
I very much enjoyed Jocks jottings - indeed a lot of the time they were my source of information at Le Mans - (mainly owing to data restraints over the years) - as Dave mentions above, Le Mans will never be quite the same.
Enjoy the racetrack in the sky, Jock.