Yeah I think you will need to get your coat as BA do not operate the B757 anymore and the 737-400s are only based out of LGW anyway and are not used at LHR!
Forgive me, I was trying to illustrate how cynical the industry is when every few years some companies undergo collective amnesia and forget where they went wrong in the past. One of the challenges some companies, not BA in particular face, is a lack of "corporate memory". Lots of MBAs with the same fresh ideas who didn't learn the harsh lessons the comany went through the last time a similar fresh initative was implemented.