Went a couple of years ago. Had a great couple of days. Groups C racers out on the track and loads of clubs and stands.
Highlight was watching the Lamborghini owners club jostling to get out of single lane car park and on to the track, no egos involved at all. http://www.0x07bell.net/SilverstoneClassic/index.html
Maybe on hold but will probably make effort to get there.
In the south west we have the powderham show but that is also on hold.