Magic.
I don't understand your problem. What's the big deal between sitting in a 80s' 737 and a 90s' / naughties 321? Do you think that a nice big polished instrument is the status symbol you need?
From your post I think I am in the same position as you with the same employer (BA). I get the impression that the GB pilots are a happy bunch. Are you not also happy with your lot at BA? GB may have some things that we don't, but we have some thing they don't (multiple bases, LH / SH to name but two).
You're probably the type of guy who buys a new car every three years and then polishes it every week. There are bigger things in life!