Tom 38 is on the right track...
I live near 7 or 8 (one of which is diseased, right outside the front door) (non native) trees and the conkers are coming along quite nicely. I've been playing since I was five years old, and supplied then entire primary school with them too. Later it become the secondary school. I've *NEVER* been short of the things. Even now I'm 40, the trees are still providing them by the carrier bagful and that includes the diseased one. I suggest Mr Flett should come up north, as they are still on the trees here. Another two weeks and they'll fall off by themselves. No need for kids to throw stuff (including their younger friends) at them as the wind is now getting up. Early October is the best time.
Coat, cos I'll be off soon to get me nephews some.