I have always put the shorter section of the Campy b.b sleeve into the fixed cup after installing the greased bearing. It is then much easier to fit the longer sleeve section when screwing in the adjustable cup. Of course it can be installed the other way as well.
To answer Bob's question, I think the Sugino accordion style b.b. sleeve works much better overall than the Campy. It is a one piece sleeve, and will fit both 70 and 68 mm b.b. shells.
Then again, most of those bicycles with the M cutout in the b.b. shell don't get ridden in inclement weather anyway, so like Tom says, why install them at all? ;-)
Jay Sexton Sebastopol, CA
A related question regarding the old Campy 2-piece crud-guards. In my experience, they work fine on Italian (70 mm.) bottom brackets, but I've had the larger sleeve split under the additional pressure when used in 68 mm bottom brackets.
Anyone else encounter this issue?
Bob Hanson, Albuquerque, New Mexico, USA