Ha! We'll both be on the hunt then! I'm in Dorset.I'm in the same boat - I'm looking for a Leaf battery pack - but at £3600-£3900, that's a lot compared to the cost of a complete car at that age and mileage.
Wrecks are still expensive unfortunately - I'd usually say Copart and local dismantlers/breakers yards - but that's still a good amount of money, and then you still have to deal with the rest of the car & the dismantling. If I had the space and time, I'd buy a wreck, part it out and sell the bits to get the pack to sort of pay for itself - but it's a lot of work for someone that doesn't do it for a living.
I'm gonna keep a close eye here to see if anyone has any good tips - sorry I didn't