For a basic Armstrong flute. I’m disabled and I need an extra length of tube or pipe to slot onto the mouthpiece end. Anybody in the Northumberland, Newcastle or Scottish Borders area who would have a go at making me one? The extra piece has to fit upto the mouthhole. At present I am trying with a tube from a bicyle pump and a piece of foam under it. It’s too light so I lift my shoulder 15 minutes later agony. Doesn’t even have to be the same material as the flute or fit permantently. I WILL find a way to play the flute. My daughter has been holding the mouthpiece in the right place for me and after a week of playing I am able to play several tunes slowly and in three octaves. I have an elbow support for my right side. 
Good for you. There are actually people who seem
to specialize in making wind instruments for
people with disabilities; in fact, I’ve seen
some designed to be played with one
hand. I can’t give any practical help,
being on the wrong side of the Big Puddle,
except to second your determination. Best
Selkie, check out the “Calling all Whistlebuilders” thread (on the Whistle Forum)! This may be of interest to you.
I’ve checked the thread out but the cost of the head joint is more than several times what I paid for the flute 
Back to the drawing board.