Breitling Navitimer

[PAMman]

I have been admiring the Breitling Navitimer and I am about to get one for myself. I have picked up a genuine dial (6, 9, 12 subdial layout) and a genuine Swiss 7750 movement so I am searching for a suitable watch to use as a base. My dial has the Arabic numbers and I understand that it should have the caseback with the temperature dial around the outside, rather than the 'fighters' pattern.

Do anyone know if the cases of the 6, 9, 12 layout differ from the 3, 6, 9 layout in dimension, as the 3,6,9 has the caseback which I want?

The reason that I think they might be different is because the 3, 6, 9 layout has transfer gears on top of the movement and therefore the distance between the front of the dial and the center of the winding stem must be greater than the model which uses the unaltered 7750 movement. Any advice would be appreciated.

Thanks.