Wotcher,
Yes, I've offloaded a couple of tickets there in the past.
An entertaining time was had when I approached the desk and said to the lovely lady 'I have some spare grandstand tickets'. In a very french accent she replied 'aaah, would you like to give me one'
Cue for every brit (and Carry On fan) within earshot to choke on their coffee.
I would like say that there was a perfect end to this story, and I took her back to my soiled tent and shagged her till I was puffing chalk dust. Instead, she sold my ticket.
H