Another mid-life career changer here. Got my first flying job, 737, early forties around 18 months ago, just before the financial shijt hit the fan. If I hadn't lucked out on my particualar path, then I'm pretty sure I wouldn't have got in at all. That is what it is all about, dogged persistence and risk taking to generate luck. However, that particular door now seems closed for quite sometime to come.
There is some new movement in jobs around the world, but forget the UK and probably Europe for a while. If you want to do this, I profer that you are going to have to be prepared to move anywhere. When the offer comes, you'll have to make a life changing and scary decisioin at the drop of a hat. You'll have litterally a couple of days to arrange your affairs before heading off to your new life. Not a business for worriers or the indecicive.
Is it worth it? For us definately. If it goes pear shaped tomorrow, it'll be stressful and frankly heartbraking; but the experience for me, my wife and kids has been priceless and opened possibilities that we would never have been receptive to before.