... so it would appear suzuki change part no's per model. which i can undestand to relate to each relevant fiche...
That is not the case - you will find many parts that ARE common across different models.
If the number is different, it means the part is different - sometimes that difference may be subtle and irrelevant to functionality - like a wheel that is different colour for example. But other while in the same 'family' may have functional spec differences of which you are unaware.
Who knows exactly what the screw difference is - it could be the length of the lever arm, the pitch of the screw, the mounting holes location and pitch .....