I don't know what make that flugel is,...I might be able to find out....
Paul Hughes who played the aqctual solo on the soundtrack has not been in Grimethorpe Colliery Band for some time and I am not sure of his whereabouts but he is very unlikely to have used a Hawkes.
The instrument held by 'Gloria' is a typical brass band type of that era,...if I had to guess, I would say it is a B&H 'Sovereign'...and this is certainly the most likely make given the circumstances. It is also very likely that Paul Hughes's flugel was a Sov. or possibly a 'French' Besson..
The recording/film was made in 1995 when there was much less penetration of foreign instrument makes in British bands,...especially in Yorkshire!
The Hawkes era flugels were good instruments in their day but have not been used by most British bands,..at least the top 20 or so, for many years. I grew up with these instruments and while they were good, they cannot really compare to modern instruments in most playing features. The truth is that despite stuff written on the web, British brass bands have changed a lot in the last generation and that includes just about all of the instruments. The modern flugels have vastly better intonation for one thing not to mention a much 'bigger' voice. Also they are radically different in their above stave characteristics,...once was the time when you could feel the tension in the rest of the band if the flugel was obliged to play above the stave,...especially in an important band contest,.....but modern flugels are a doddle!
You could e-mail/message the band here;
http://www.grimethorpeband.com/