Hello Jenny
I am actually only a few miles from you.
Are you looking for some trumpet playing experience?
The Open Orchestra in Edinburgh currently has scholarship places (i.e. no fee) for students wanting playing experience.
Generally you need to be grade five or above but there is no audition.
The standard is actually quite high in spite of this. There are quite a few ex pros in the orchestra and people who maybe studies music but did not take it up professionally.
The current program has one piece that needs an extra trumpet player.
Next season there is lots of larger brass parts.
It might be worth checking it out:
http://www.blackford.demon.co.uk/open-orchestra/