This is an interesting debate. Why should the model of concorde be kept? For the same reason we build statues of long dead national heroes, for the same reason we take our children to museums, for the same reason we save old aircraft like the Lancaster and spitfire flying..........because we have a proud history of success in this nation and consigning everything to a history book and without any visual reminders we will become exactly what some in high place want us to be; a bland and soulless nation without any character. It might cost 1.5 million, which is a price worth paying for all the millions of visitors that pass by and are reminded that the UK once lead the world in a certain area of aviation. Maybe the lottery should pay for it to stay?
By all means put something there that is perhaps a monument to LHR, or something similar.
And instead of getting the lottery to pay £1.5m to keep the model there, I'd far rather see a donation of £1.5m to one of the museums that currently has a full size model of Concorde so it can be well looked after.
I just think it's a bit silly for BA to advertise their services by reminding passengers of their past!