To be honest I would rather just ride to Rye and not worry about the show. You never know others may be interested in a meet up at Dungy for refreshments.
It's the West Kent Classic Run. For the owners of old brit bangers it starts on the Thursday but the site is open to other peeps on the Sunday for £4 a head.
Went a few years back and it was pretty good, loads of bikes. The rally part of the run is full and so I expect as long as the weather is good it will be a good show.