Thanks fossyant! Having just bought a new winter bike with Shimano, (I'm used to Campag), I also was wondering about the trim.
In relation to the Shimano/Campag divide; I have some excellent wheels from Pete Matthews which have Chorus hubs and wished to use them on this Shimano geared bike. With a spacer kit supplied by Highpath Engineering of Newtown you can convert a Chorus hub with Campag sprockets so that it operates smoothly with Shimano gears.
Highpath also give a selection of packing spacers, as Campag clusters are wider than Shimano. This is not a puff-piece for Highpath, but their help is second to none!