I ordered 4 x A Class in a single order (with nothing else) and got the warning but none of these are stock items yet, right? They all said "pre order" as far as I can recall. I just noticed this thread now. Maybe someone needs to check that all the A classes are correctly configured in the shop system unless some are actually in stock now?
I ordered the 4 IR tippex liveried ones.
Also, now that I'm writing about my order experience, I should let you know that the initial checkout screen is confusing as it lists the items ex-Vat which is not common in online retail. You see the retail price Inc Vat everywhere usually, from start to finish of the checkout process. Maybe it's intentional but it is unusual and I wondered what was going on for a moment.