I guess you are asking because you don't have another BA booking at the moment: the print/email receipt is online and instant, and I've just checked one of my bookings and it came out fine. I would put an example online but it's covered from head to toe in personal data and credit card information, however I will PM you the PDF if you wish. The correct receipt doesn't give the fare bucket or fare basis but does have the fare breakdown, APD, charges and so on. And it does spell out the cabin too (EuroTraveller / Club Europe etc).

I suspect the problem you had with the change you made is that it then went off self-serve and off to manual ticketing which could have happened hours before flying (or may have been near instant). At least in theory, after ticketing and before the flight the receipt should have been visible.