''The principle remains the same. A fun day in Brighton for as big a crowd as wishes to join us.''
That crowd has steadily increased.
In the early days the event attracted about 1000 people, now this number exceeded 10,000, he said. On its best years this topped 15,000.
The Brighton Domain is expected to be packed on Sunday for this year's event.
Mr Weatherall and family members started it to ''give something back'' to Brighton, where they lived much of their life.
It was initially held on a Saturday to coincide with the Dunedin to Brighton Veteran Car Rally, but Mr Weatherall eventually found Sundays worked better.
It was fairly unique in that it continued to have free entry, he said.
''There are challenges in maintaining that, but we've had great help from sponsors.''
This year stall numbers were capped at 180, to allow a little more public space, he said.
It would be a ''huge'' weekend for the area, with the Taieri A & P show in Mosgiel on the Friday and Saturday.
''The only apology we make is that parking might be scarce.''