We (Rivington Riflemen) did a similar fair a few months ago (http://www.airgunbbs.com/showthread....ight=Adlington) in aid of Cancer Research and in memory of my pal Ray Ross.
Like the Melbourne event which I have attended a few times, it was a great day out. I bought some bargains, sold some tat , had a great laugh and even got some one with the 'smelly grease' trick.

Go for it!