Hi there Big Boy. One word concerning your proposed move into the aviation maintenance field. DON'T!!!!! As a mech or tech you are considered to be a second class citizan by other fields in the airline world, you will not have the respect that you deserve, and you will be expected to work the most anti-social hours in the most anti-social environment. If I had my time again I would consider learning how to fly rather than maintain aircraft.
If you haven't been totally put off when this thread has run it's course, then there some places that may consider adult trainees. Try Monarch at Luton, of FLS Aerospace at Stanstead. But whatever happens, best of luck and I hope that you find what you are looking for.
JFD.