If your music is missing a part put out a request here. Please remember that photocopying music is always illegal so get the appropriate permission first
I know the original guitar work is published by Schott (Great Marlborough St., London). They may be able to advise you as to where to get parts for the Brass Band set.
gjwhite:
best not, because the brass band version is 100% illegal
it was never published because a "mrs Rodrigo" and the society decided that they would argue because they were not consulted about its use in Brassed off.
If the original writer wants just the part there are two so ill need to know which they want ( theres the simple and the modified(used in the film))
There is (or perhaps that should be was because I think permission has been removed for this as well) a legal band arrangment by Darrol Barry - but this version was not as a flugel solo.
You're quite right about the flugel solo version. If you did get hold of a copy and wanted to perform/record it you would need to get permission from the copyright holder first. It is best to avoid the piece because of the legal problems.