Progress... MY 256GB Black Plus (20-22 window) is still showing "Processing Items" on Apple website but have received a text from UPS telling me that a shipment from APPLE INC FG C-O TECH-FULL COMPUTER has shipped and should be delivered on 22/09/2016 by end of day... So it looks like it will make the window!
Although I changed the delivery location last week and the UPS app is still showing the original location (the Apple website is right). Hopefully that will resolve itself before Thursday...