They're different shapes for sure, the '21 tank has a square back, the '28 is like a launch ramp. It may well "fit", a mk2 escort bonnet fits a mk1. Wheather it looks right is another thing, and depends on how you define "right".
Personnally I like the little vents either side of the '28 lights, but then again I like the SS swingarm
I believe the bottom and mid panels are the same, I chuck mine in the van and we'll double check.
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