Welcome.
As I understood it, there's only one rotor type for a curvy
https://www.fowlersparts.co.uk/parts...sk1suk1sk2suk2 (item 23A 34983-21E00).
There is a different rotor for the later "pointys".
Is there any chance that someone fitted a "healer" to make your km speedo read mph? This person seemed to have a similar issue and found a "black box" fitted in the cable loom:
https://forums.sv650.org/showthread.php?t=206237
there's a picture in post #7.