The shims will come with it new (well should), though you'll be wanting the FD-M771 version for a lavadome as it has an ovalised seattube at the bottom bracket, though thinking about it I'm not really sure with the 1996 model ?
Check and see which version was on when it was new.
SM-AD16S are the official shims for it (34.9 to 26.
EDIT catalogue shows M771 style, you'll need Anthony or somebody else who knows to tell you if any other version will work