Olwell Pratten and Nicholson physical differences.

Hi all,
Just a quick question regarding Olwell flutes, the Pratten and the Nicholson models, I’m looking at one on
Monday morning, the owner has no idea which it is, all I know is it’s one of the two, and consist of headjoint, tuning barrel mid section with all six holes and footjoint, I’m guessing his Rudall model is a 5 piece and not
4 piece, So is there anyway of telling which Olwell flute it might be, as the sound is describe as big on both, I don’t think it will be easy to tell by sound alone, so are there any clear cut dimensional identifications.

All the best Yvie