Dave.
The info that Richard Sach's n Brian Baylis gave you are correct. The
Nervex bb might be undersized in width and off center on it's width
dimensions. This can make your project difficult. Of course, if you have a
lathe, you can make a spacer to be brazed to the short side of the bb; you
can also try an old steel freewheel spacer and braze that to the bb .
Good luck, if I can give help to you let me know.
Anthony
Mezzatesta