Thank you for the responses. It seems I can helicoil the Magteks and use a regular bolt without having to use a longer bolt going right through with a nut.
I have looked at some of the SP parts lists but I can only find short bolts. Does anyone know the exact model code or HRC listing that would show especially the Magtek with straight through bolts - I am rebuilding an MC21 but I don't think the owner necessarily bought a Magtek from an MC21 - it's a bit hit and miss...which is not good with brake fixings!!

I spend a lot of time on the Aprilia forums because I have 3 RS250s so it's nice to find like minded people all pulling together to make the hobby fun (especially with so much aggression in the World ). Thanks again, Paul