There are two ways to handle the procedure: one if you don’t mind a trip to Amsterdam, where I live. You would then visit my workshop, and I construct a dummy adaptation on the spot. You will be able to judge and refine my proposition then and there. I will then quote a price for the work to be done, and when you accept, I’ll make the requested headjoint/ adaptations.
Amsterdam is a gorgeous place, but I can imagine it’s a bit much of a trip. So the alternative option is to do things by email and skype. I ask questions, You answer,and I finally construct a dummy flute which I send to you by snailmail so you can feel how it would be to play a swan-neck or verical flute. For most people the standard test set dummies for Swan Neck/Vertical headjoint are fine.