I ticked the box to use eBays 'Global Shipping Programme'. By all accounts eBay take care of the overseas bit. UK sellers pay UK postage to send to the GSP centre. EBay will have already notified the overseas purchaser of postage. Apparently.
So many people ask for WOTW, I'm surprised it didn't go for more. Maybe people are holding out for the budget version but honestly with how impatient these newer people are, I still thought it'd have gone for more.