Sean,
I'm not scheduled to get into Heathrow until 7:40AM on Wednesday, so it seems we wouldn't be able to start at Kington until early afternoon.
Agreed it would work out better travel-wise to play Burnham first, but we wanted to play with the group James is organizing for Thursday PM. It's an extra hundred miles or so of driving, but we're also hoping to see Painswick early on Thursday as well. So I think worth it.