There's nothing unique about 1989. From day one, Tange #1 through #5 used the same same blades (i.e.made of the same material with the same thickness). In fact, if Infinity, 900 and 1000 weren't seamed, they'd be the same too. Options were things the profile required for the desired crown, rake and dropouts. You had to step up to Pro/Prestige to get something that was truly different. That's why all the all those early Ironman had red Tange decals on the forks, while they had the blue #1 decals on the seat tube, because Tange had one basic fork blade design used on #1 though #5 and they all used the red decal.