Does anyone know if the Dixon flute top can be adapted to replace the head of a Susato low D? If not,any comments on the Dixon Duo would be appreciated. 
Mike
As we say in the SCA: Anything is Possible with Duct Tape! 
However, you might have some trouble as the two headjoint/body configurations are different. The Dixon headjoint fits into a sleeve that’s attached to the body. Whereas the on the Susato, the sleeve is part of the headjoint. Maybe with a hack-saw…(shudder)
As far as the Dixon. I think I like the Tone of the Dixon better than most of my other PVC whistles. Some people (including myself) have found that the tuning is off on the Dixon - But my Generation D is far worse.
Good Luck! If you do get the two together I want to see a photo of your “Whistle”-stein monster. 
-Frank
Thank you Frank,its a shame Susato dont offer this as their intonation is spot on.Maybe I can make my own ,cant hurt to try.Are both Dixon heads the same length ?and is the flute hole in the same location as the whistle window? Cheers Mike