The second set are definately stock MC21 calipers. That is what I used on my '89 RS fork conversion. The third set are definately MC28 stock calipers. The first set, though, I am not sure about. Probably the stock RS250 calipers that belong on forks like mine.
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Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
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