Great idea fellas, I'll put in.
The only thing I would mention is that if you're going to fly it over the Custard Bowl then it's fairly evident that the motivation behind it is to take the pee. I'm not sure as 'Boing Boing' or 'Pride of the Midlands' or whatever really achieves that.
I think something simple but a little bit caustic, perhaps the aforementioned 'CHEERIO WO1LVE5 / GOODBYE DINGLES', or even 'THE BLACK COUNTRY'S OURS' would make more sense for this particular endeavour.
Anyway, just a quick thought. Good luck in getting it sorted.