Polini Exhaust not fitting on PK125

Bought a Polini left hand pipe for PK125 a while ago and just got round to fitting it but it won't go on. If I slip the main part into the manifold the mount on the exhaust hits the scooter frame about 2cm too far forward.  If I fit exhaust bracket to mounting bolt the slip joint only just touches and if I force spring on it pulls the bottom of the manifold away from the barrel.

The one I ordered from SIP was for a PK125 but have I got a wrong manifold? Not got packaging but number stamped on exhaust looks like DGM N 37519 S.



I don't know if it will be the problem or not, but could the exhaust be designed to match a 130cc polini cylinder kit?